Methods and apparatus for predicting performance of a measurement method, measurement method and apparatus

Metrology in lithographic processes

An apparatus and method for estimating a parameter of a lithographic process and an apparatus and method for determining a relationship between a measure of quality of an estimate of a parameter of a lithographic process are provided. In the apparatus for estimating the parameter a processor is configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features.

Metrology apparatus, lithographic system, and method of measuring a structure

A metrology apparatus is disclosed that measures a structure formed on a substrate to determine a parameter of interest. The apparatus comprises an optical system configured to focus radiation onto the structure and direct radiation after reflection from the structure onto a detector, wherein: the optical system is configured such that the detector detects a radiation intensity resulting from interference between radiation from at least two different points in a pupil plane field distribution, wherein the interference is such that a component of the detected radiation intensity containing information about the parameter of interest is enhanced relative to one or more other components of the detected radiation intensity.

Position measurement with illumination profile having two diametrically opposed off-axis radiation

An apparatus (AS) measures positions of marks ( 202 ) on a lithographic substrate (W). An illumination arrangement ( 940, 962, 964 ) provides off-axis radiation from at least first and second regions. The first and second source regions are diametrically opposite one another with respect to an optical axis (O) and are limited in angular extent. The regions may be small spots selected according to a direction of periodicity of a mark being measured, or larger segments. Radiation at a selected pair of source regions can be generated by supplying radiation at a single source feed position to a self-referencing interferometer. A modified half wave plate is positioned downstream of the interferometer, which can be used in the position measuring apparatus. The modified half wave plate has its fast axis in one part arranged at 45° to the fast axis in another part diametrically opposite.

Alignment sensor and lithographic apparatus

An alignment sensor for a lithographic apparatus is arranged and constructed to measure an alignment of a movable part of the lithographic apparatus in respect of a stationary part of the lithographic apparatus. The alignment sensor comprises a light source configured to generate a pulse train at a optical wavelength and a pulse repetition frequency, a non-linear optical element, arranged in an optical propagation path of the pulse train, the non-linear optical element configured to transform the pulse train at the optical wavelength into a transformed pulse train in an optical wavelength range, an optical imaging system configured to project the transformed pulse train onto an alignment mark comprising a diffraction grating; a detector to detect a diffraction pattern as diffracted by the diffraction grating, and a data processing device configured to derive alignment data from the detected diffraction pattern as detected by the detector.

POSITION SENSOR, LITHOGRAPHIC APPARATUS AND METHOD FOR MANUFACTURING DEVICES

An alignment sensor for a lithographic apparatus has an optical system configured to deliver, collect and process radiation selectively in a first waveband (e.g. 500-900 nm) and/or in a second waveband (e.g. 1500-2500 nm). The radiation of the first and second wavebands share a common optical path in at least some portion of the optical system, while the radiation of the first waveband is processed by a first processing sub-system and the radiation of the second waveband is processed by a second processing sub-system. The processing subsystems in one example include self-referencing interferometers. The radiation of the second waveband allows marks to be measured through an opaque layer. Optical coatings and other components of each processing sub-system can be tailored to the respective waveband, without completely duplicating the optical system. 1. A position sensor comprising an optical system configured to deliver radiation to an alignment mark on a substrate and to collect diffracted or scattered radiation from the substrate , and to process the collected radiation to derive at least one position-sensitive signal therefrom , wherein the optical system is configured to deliver , collect and process radiation selectively in a first wavelength range and/or in a second wavelength range , wherein the radiation of the first wavelength range and the second wavelength range share a common optical path in at least a common objective lens , the optical system configured to simultaneously deliver the radiation of both the first and second wavelength ranges via the common objective lens onto the same alignment mark and collect the diffracted or scattered radiation from the substrate , and wherein the radiation of the first wavelength range is processed by a first processing sub-system and the radiation of the second wavelength range is processed by a second processing sub-system.2. The position sensor as claimed in claim 1 , wherein the first wavelength range includes ...

LEVEL SENSOR ARRANGEMENT FOR A LITHOGRAPHY DEVICE, A LITHOGRAPHY DEVICE, AND A METHOD FOR MANUFACTURING A DEVICE CAPABLE OF OBTAINING INFORMATION ABOUT A COMPLETE STACK

PURPOSE: A level sensor arrangement for a lithography device, a lithography device, and a method for manufacturing a device are provided to accurately determine the uppermost surface of a resist by tracking the maximum values of peaks as an incident spectrum function. CONSTITUTION: An illumination beam is split into two beams by a beam splitter(460). A first beam is oriented to a wafer(440) along a first path(p1). A second beam is oriented to a reference mirror(450) along a second path(p2). Light reflected from a mirror and the wafer is combined along a third path(p3). A detector(430) induces an interference pattern in a CCD or CCD array and a photodiode or a photodiode array. The intensity of incident light from the detector is changed by scanning the length of the second path. COPYRIGHT KIPO 2013 ...

Computer program product, method and inspection apparatus for measuring properties of a target structure, and method of manufacturing devices

A metrology device configured to produce measurement illumination comprising a plurality of illumination beam, and a lithographic apparatus

Metrology sensor for position metrology

Disclosed is a metrology device configured to produce measurement illumination comprising a plurality of illumination beams, each of said illumination beams being spatially incoherent or pseudo-spatially incoherent and comprising multiple pupil points in an illumination pupil of the metrology device. Each pupil point in each one of said plurality of illumination beams has a corresponding pupil point in at least one of the other illumination beams of said plurality of illumination beams thereby defining multiple sets of corresponding pupil points, and the pupil points of each set of corresponding pupil points are spatially coherent with respect to each other.

Method for overlay metrology and apparatus thereof

A method includes receiving an image formed in a metrology apparatus wherein the image comprises at least the resulting effect of at least two diffraction orders, and processing the image wherein the processing comprises at least a filtering step, for example a Fourier filter. The process of applying a filter may be obtained also by placing an aperture in the detection branch of the metrology apparatus.

Mark position measuring apparatus and method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an illumination arrangement to direct radiation across a pupil of the apparatus, the illumination arrangement including an illumination source to provide multiple-wavelength radiation of substantially equal polarization and a wave plate to alter the polarization of the radiation in dependency of the wavelength, such that radiation of different polarization is supplied; an objective to direct radiation on the mark using the radiation supplied by the illumination arrangement while scanning the radiation across the mark in a scanning direction; a radiation processing element to process radiation that is diffracted by the mark and received by the objective; and a detection arrangement to detect variation in an intensity of radiation output by the radiation processing element during the scanning and to calculate from the detected variation a position of the mark in at least a first direction of measurement.

Method and apparatus for determining the property of a structure, device manufacturing method

Method to Determine a Patterning Process Parameter

A method to determine a patterning process parameter, the method comprising: for a target, calculating a first value for an intermediate parameter from data obtained by illuminating the target with radiation comprising a central wavelength; for the target, calculating a second value for the intermediate parameter from data obtained by illuminating the target with radiation comprising two different central wavelengths; and calculating a combined measurement for the patterning process parameter based on the first and second values for the intermediate parameter.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an inspection apparatus and associated method for measuring a target structure on a substrate. The inspection apparatus comprises an illumination source for generating measurement radiation; an optical arrangement for focusing the measurement radiation onto said target structure; and a compensatory optical device. The compensatory optical device may comprise an SLM operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in said optical arrangement. In alternative embodiments, the compensatory optical device may be located in the beam of measurement radiation, or in the beam of pump radiation used to generate high harmonic radiation in a HHG source. Where located in the beam of pump radiation, the compensatory optical device may be used to correct pointing errors, or impart a desired profile or varying illumination pattern in a beam of the measurement radiation.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Position measuring method, lithographic appratus, lithocell and device manufacturing method

Apparatus for delivering gas and illumination source for generating high harmonic radiation

Disclosed is gas delivery system which is suitable for a high harmonic generation (HHG) radiation source which may be used to generate measurement radiation for an inspection apparatus. In such a radiation source, a gas delivery element delivers gas in a first direction. The gas delivery element has an optical input and an optical input, defining an optical path running in a second direction. The first direction is arranged relative to the second direction at an angle that is not perpendicular or parallel. Also disclosed is a gas delivery element having a gas jet shaping device, or a pair of gas delivery elements, one of which delivers a second gas, such that the gas jet shaping device or second gas is operable to modify a flow profile of the gas such that the number density of the gas falls sharply.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes a sensor, such as an alignment sensor including a self-referencing interferometer, configured to determine the position of an alignment target including a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans the structure. Multiple position-dependent signals are detected and processed to obtain multiple candidate position measurements. Asymmetry of the structure is calculated by comparing the multiple position-dependent signals. The asymmetry measurement is used to improve accuracy of the position read by the sensor. Additional information on asymmetry may be obtained by an asymmetry sensor receiving a share of positive and negative orders of radiation diffracted by the periodic structure to produce a measurement of asymmetry in the periodic structure.

Methods and apparatus for predicting performance of a measurement method, measurement method and apparatus

Target structures such as overlay gratings (Ta and Tb) are formed on a substrate (W) by a lithographic process. The first target is illuminated with a spot of first radiation (456a, Sa) and simultaneously the second target is illuminated with a spot of second radiation (456b, Sb). A sensor (418) detects at different locations, portions (460x−, 460x+) of said first radiation that have been diffracted in a first direction by features of the first target and portions (460y−, 460y+) of said second radiation that have been diffracted in a second direction by features of the second target. Asymmetry in X and Y directions can be detected simultaneously, reducing the time required for overlay measurements in X and Y. The two spots of radiation at soft x-ray wavelength can be generated simply by exciting two locations (710a, 710b) in a higher harmonic generation (HHG) radiation source or inverse Compton scattering source.

Alignment system

An alignment system, method and lithographic apparatus are provided for determining the position of an alignment mark, the alignment system comprising a first system configured to produce two overlapping images of the alignment mark that are rotated by around 180 degrees with respect to one another, and a second system configured to determine the position of the alignment mark from a spatial distribution of an intensity of the two overlapping images.

Metrology method and apparatus and computer program

Disclosed are a method, computer program and a metrology apparatus for measuring a process effect parameter relating to a manufacturing process for manufacturing integrated circuits on a substrate. The method comprises determining for a structure, a first quality metric value for a quality metric from a plurality of measurement values each relating to a different measurement condition while cancelling or mitigating for the effect of the process effect parameter on the plurality of measurement values and a second quality metric value for the quality metric from at least one measurement value relating to at least one measurement condition without cancelling or mitigating for the effect of the process effect parameter on the at least one measurement value. The process effect parameter value for the process effect parameter can then be calculated from the first quality metric value and the second quality metric value, for example by calculating their difference.

Metrology method

A method provides the steps of receiving an image from a metrology tool, determining individual units of said image and discriminating the units which provide accurate metrology values. The images are obtained by measuring the metrology target at multiple wavelengths. The discrimination between the units, when these units are pixels in said image, is based on calculating a degree of similarity between said units.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes an alignment sensor including a self-referencing interferometer for reading the position of a mark including a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans said structure. Multiple position-dependent signals are detected in a detection optical system and processed to obtain multiple candidate position measurements. Each mark includes sub-structures of a size smaller than a resolution of the optical system. Each mark is formed with a positional offset between the sub-structures and larger structures that is a combination of both known and unknown components. A measured position of at least one mark is calculated using signals from a pair of marks, together with information on differences between the known offsets, in order to correct for said unknown component of said positional offset.

Methods and patterning devices and apparatuses for measuring focus performance of a lithographic apparatus, device manufacturing method

A lithographic apparatus (LA) prints product features and at least one focus metrology pattern (T) on a substrate. The focus metrology pattern is defined by a reflective reticle and printing is performed using EUV radiation (404) incident at an oblique angle (θ). The focus metrology pattern comprises a periodic array of groups of first features (422). A spacing (S1) between adjacent groups of first features is much greater than a dimension (CD) of the first features within each group. Due to the oblique illumination, the printed first features become distorted and/or displaced as a function of focus error. Second features 424 may be provided as a reference against which displacement of the first features may be seen. Measurement of this distortion and/or displacement may be by measuring asymmetry as a property of the printed pattern. Measurement can be done at longer wavelengths, for example in the range 350-800 nm.

Lithographic Apparatus and Method for Performing a Measurement

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). The lithographic apparatus has an inspection apparatus with an illumination system that utilizes illuminating radiation with a wavelength of 2-40 nm. The illumination system includes an optical element that splits the illuminating radiation into a first and a second illuminating radiation and induces a time delay to the first or the second illuminating radiation. A detector detects the radiation that has been scattered by a target structure. The inspection apparatus has a processing unit operable to control a time delay between the first scattered radiation and the second scattered radiation so as to optimize a property of the combined first and second scattered radiation.

Methods and apparatus for predicting performance of a measurement method, measurement method and apparatus

A metrology apparatus (302) includes a higher harmonic generation (HHG) radiation source for generating (310) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor (420) which comprises an aperture array (424, 702) and an image sensor (426). A grating (706) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings (706) of each subset having a different direction of dispersion. The spectrally resolved wavefront information (430) is used in feedback control (432) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

POSITION MEASURING METHOD OF AN ALIGNMENT TARGET

A method of measuring a position of an alignment target on a substrate using an optical system. The method includes measuring a sub-segmented target by illuminating the sub-segmented target with radiation and detecting radiation diffracted by the sub-segmented target using a detector system to obtain signals containing positional information of the one sub-segmented target. The sub-segmented target has structures arranged periodically in at least a first direction, at least some of the structures including smaller sub-structures, and each sub-segmented target is formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components. The signals, together with information on differences between known offsets of the sub-segmented target are used to calculate a measured position of an alignment target which is corrected for the unknown component of the positional offset. 1. A method comprising:measuring a sub-segmented target by illuminating the sub-segmented target with radiation and detecting radiation diffracted by the sub-segmented target using a detector system to obtain signals containing positional information of the sub-segmented target, the measuring performed on the sub-segmented target when the sub-segmented target is still in resist, the sub-segmented target comprising structures arranged periodically in at least a first direction, at least some of the structures comprising smaller sub-structures, and the sub-segmented target formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components;using the signals, together with information on differences between the known offsets of the sub-segmented target, to calculate a measured position of an alignment target on a substrate which is corrected for the unknown component of the positional offset.2. The method as claimed in claim 1 , comprising determining a measure of ...

Alignment Sensor and Lithographic Apparatus

An alignment sensor for a lithographic apparatus is arranged and constructed to measure an alignment of a movable part of the lithographic apparatus in respect of a stationary part of the lithographic apparatus. The alignment sensor comprises a light source configured to generate a pulse train at a optical wavelength and a pulse repetition frequency, a non-linear optical element, arranged in an optical propagation path of the pulse train, the non-linear optical element configured to transform the pulse train at the optical wavelength into a transformed pulse train in an optical wavelength range, an optical imaging system configured to project the transformed pulse train onto an alignment mark comprising a diffraction grating; a detector to detect a diffraction pattern as diffracted by the diffraction grating, and a data processing device configured to derive alignment data from the detected diffraction pattern as detected by the detector. 1. An alignment sensor for a lithographic apparatus , the alignment sensor being arranged and constructed to measure an alignment of a movable part at the lithographic apparatus in respect of a stationary part of the lithographic apparatus , the alignment sensor comprising:a light source configured to generate a pulse train at a optical wavelength and a pulse repetition frequency,a non-linear optical element, arranged in an optical propagation path of the pulse train, the non-linear optical element being configured to transform the pulse train at the optical wavelength into a transformed pulse train in an optical wavelength range,an optical imaging system configured to project the transformed pulse train onto an alignment mark;a detector configured to detect a scattered field as scattered by the alignment mark, anda data processing device configured to derive alignment data from the detected scattered field as detected by the detector,wherein the optical imaging system comprises a pulse delay generator,the pulse delay generator ...

Substrate edge detection

A method including directing, by an optical system, an illumination beam to a surface of a substrate, providing relative motion between the directed illumination beam and the substrate until the directed illumination beam is illuminated on a grating underneath an edge or a notch of the substrate, diffracting, by the grating, at least a portion of the illumination beam, and detecting, by the detector, the diffracted illumination.

Position measuring method of an alignment target

A method of measuring a position of an alignment target on a substrate using an optical system. The method includes measuring a sub-segmented target by illuminating the sub-segmented target with radiation and detecting radiation diffracted by the sub-segmented target using a detector system to obtain signals containing positional information of the one sub-segmented target. The sub-segmented target has structures arranged periodically in at least a first direction, at least some of the structures including smaller sub-structures, and each sub-segmented target is formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components. The signals, together with information on differences between known offsets of the sub-segmented target are used to calculate a measured position of an alignment target which is corrected for the unknown component of the positional offset.

Position measuring method, lithographic appratus, lithocell and device manufacturing method

Disclosed is a method of measuring positions of at least one alignment target on a substrate using an optical system. The method comprises measuring at least one sub-segmented target by illuminating said sub-segmented target with radiation and detecting radiation diffracted by said sub-segmented target using one or more detectors to obtain signals containing positional information of the sub-segmented target. The sub-segmented target comprise structures arranged periodically in at least a first direction, at least some of said structures comprising smaller sub-structures, each sub-segmented target being formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components. The signals, together with information on differences between known offsets of the sub-segmented target are used to calculate a measured position of at least one alignment target which is corrected for said unknown component of said positional offset.

ALIGNMENT METHOD

A method of determining the position of an alignment mark on a substrate, the alignment mark having first and second segment, the method including illuminating the alignment mark with radiation, detecting radiation diffracted by the alignment mark and generating a resulting alignment signal. The alignment signal has a first component received during illumination of the first segment only, a second component received during illumination of the second segment only, and a third component received during simultaneous illumination of both segments. The positions of the segments are determined using the first component, the second component and the third component of the alignment signal. 1. A method of determining the position of an alignment mark on a substrate , the alignment mark comprising a first segment and a second segment , the method comprising:illuminating the alignment mark with radiation, detecting radiation diffracted by the alignment mark and generating a resulting alignment signal, the alignment signal comprising a first component received during illumination of the first segment only, a second component received during illumination of the second segment only, and a third component received during simultaneous illumination of both first and second segments; anddetermining the positions of the first and second segments using the first component, the second component and the third component of the alignment signal, the determining including deconvolvinq the third component of the alignment signal.2. The method of claim 1 , wherein the determining uses the results of a calibration measurement on a calibration mark having known characteristics to produce a calibration alignment signal from which a relationship between the alignment signal and the positions of the first and second segments may be determined.3. The method of claim 2 , wherein the determining includes fitting the calibration alignment signal to the alignment signal.4. (canceled)5. The method of ...

Method and apparatus for measuring asymmetry of a microsutructure, position measuring method, position measuring apparatus, lithographic apparatus and semiconductor device manufacturing method

Inspection apparatus, inspection method and manufacturing method

Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation (650) diffracted by from said target area interferes with reference radiation (652) interferes with to form an interference pattern at an image detector (623). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image (814) of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (814, 814′) of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry.

Metrology sensor, lithographic apparatus and method for manufacturing devices

Disclosed is a metrology sensor apparatus and associated method. The metrology sensor apparatus comprises an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state and an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark. The metrology mark comprises a main structure and changes, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to the polarization state of the second portion of the scattered radiation. The metrology sensor apparatus further ...

Method and apparatus for generating illuminating radiation

Method and apparatus for determining the property of a structure, device manufacturing method

A structure of interest (T) is irradiated with radiation for example in the x-ray or EUV waveband, and scattered radiation is detected by a detector (19, 274, 908, 1012). A processor (PU) calculates a property such as linewidth (CD) or overlay (OV), for example by simulating (S16) interaction of radiation with a structure and comparing (S17) the simulated interaction with the detected radiation. The method is modified (S14a, S15a, S19a) to take account of changes in the structure which are caused by the inspection radiation. These changes may be for example shrinkage of the material, or changes in its optical characteristics. The changes may be caused by inspection radiation in the current observation or in a previous observation.

Metrology parameter determination and metrology recipe selection

A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.

MEASUREMENT METHOD AND ASSOCIATED DEVICE

A metrology method is disclosed. The method comprises: measuring at least one surrounding observable parameter relating to surrounding signal contributions to a metrology signal, the surrounding signal contributions comprising contributions to the metrology signal that are not attributable to at least one target being measured; and determining a correction from the ambient signal observable parameter. The correction is used to correct first measurement data relating to a measurement of one or more targets using measurement radiation that forms a measurement spot on one or more of the one or more targets that is larger than one of the targets.

HHG source, inspection apparatus and method for performing a measurement

Disclosed is a method of performing a measurement in an inspection apparatus, and an associated inspection apparatus and HHG source. The method comprises configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control the output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; and illuminating a target structure with said illuminating radiation. The method may comprise configuring the driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks. Alternatively the method may comprise using a plurality of driving laser pulses of different wavelengths such that the output emission spectrum is substantially monochromatic.

Illumination Source for an Inspection Apparatus, Inspection Apparatus and Inspection Method

Disclosed is an inspection apparatus and associated method for measuring a target structure on a substrate. The inspection apparatus comprises an illumination source for generating measurement radiation; an optical arrangement for focusing the measurement radiation onto said target structure; and a compensatory optical device. The compensatory optical device may comprise an SLM operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in said optical arrangement. In alternative embodiments, the compensatory optical device may be located in the beam of measurement radiation, or in the beam of pump radiation used to generate high harmonic radiation in a HHG source. Where located in the beam of pump radiation, the compensatory optical device may be used to correct pointing errors, or impart a desired profile or varying illumination pattern in a beam of the measurement radiation. 1. An illumination source for generating high harmonic radiation , comprising:a high harmonic generation medium;a pump radiation source configured to emit a beam of pump radiation to excite the high harmonic generation medium to generate high harmonic radiation; anda compensatory optical device operable to spatially modulate a wavefront of the beam of pump radiation prior to it exciting the high harmonic generation medium.2. The illumination source of claim 1 , wherein the compensatory optical device is operable to spatially modulate the wavefront of the beam of pump radiation so as to correct a position error of a beam of the high harmonic radiation.3. The illumination source of claim 2 , wherein the illumination source is configured to:receive a position signal describing the position of a focused point of a beam wherein the beam is the beam of pump radiation or the beam of the high harmonic radiation;determine a correction for the position of the focused point of the beam relative to a desired position in terms of a ...

MEASUREMENT METHOD FOR MEASURING AN ETCH TRENCH AND RELATED MEASUREMENT DEVICE

A method of determining at least one uniformity metric that describes a uniformity of an etched trench formed by a lithographic manufacturing process on a substrate is disclosed. The method comprises obtaining one or more images of the etched trench, where each of the one or more images comprises a spatial representation of one or more parameters of scattered radiation detected by a detector or camera after scattering and/or diffraction from the etched trench; and measuring uniformity along the length of the etched trench on the one or more images to determine at least one uniformity metric.

Lithographic apparatus and method for performing a measurement

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). The lithographic apparatus has an inspection apparatus with an illumination system that utilizes illuminating radiation with a wavelength of 2-40 nm. The illumination system includes an optical element that splits the illuminating radiation into a first and a second illuminating radiation and induces a time delay to the first or the second illuminating radiation. A detector detects the radiation that has been scattered by a target structure. The inspection apparatus has a processing unit operable to control a time delay between the first scattered radiation and the second scattered radiation so as to optimize a property of the combined first and second scattered radiation.

Methods and Patterning Devices and Apparatuses for Measuring Focus Performance of a Lithographic Apparatus, Device Manufacturing Method

A lithographic apparatus (LA) prints product features and at least one focus metrology pattern (T) on a substrate. The focus metrology pattern is defined by a reflective reticle and printing is performed using EUV radiation ( 404 ) incident at an oblique angle (θ). The focus metrology pattern comprises a periodic array of groups of first features ( 422 ). A spacing (S 1 ) between adjacent groups of first features is much greater than a dimension (CD) of the first features within each group. Due to the oblique illumination, the printed first features become distorted and/or displaced as a function of focus error. Second features 424 may be provided as a reference against which displacement of the first features may be seen. Measurement of this distortion and/or displacement may be by measuring asymmetry as a property of the printed pattern. Measurement can be done at longer wavelengths, for example in the range 350-800 nm.

Inspection Apparatus and Methods, Substrates Having Metrology Targets, Lithographic System and Device Manufacturing Method

Disclosed is an inspection apparatus for use in lithography. It comprises a support for a substrate carrying a plurality of metrology targets; an optical system for illuminating the targets under predetermined illumination conditions and for detecting predetermined portions of radiation diffracted by the targets under the illumination conditions; a processor arranged to calculate from said detected portions of diffracted radiation a measurement of asymmetry for a specific target; and a controller for causing the optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and calculate from the results of said asymmetry measurements a measurement of a performance parameter of the lithographic process for structures of said smaller size. Also disclosed are substrates provided with a plurality of novel metrology targets formed by a lithographic process. 1. A method comprising:{'sup': 'st', 'measuring a −1order scatterometry image of gratings on a substrate with offsets between populations using a first illumination mode;'}{'sup': 'st', 'measuring a +1order scatterometry image of the gratings using a second illumination mode;'}{'sup': st', 'st, 'determining a region of interest in each of the gratings from the −1order and +1order scatterometry images;'}{'sup': st', 'st, 'calculating a difference image of each of the gratings from the −1order and +1order scatterometry images to determine a difference in intensity;'}determining a parameter of a lithographic process between the populations based on the difference in intensity; andcorrecting for at-resolution offsets based on the difference in intensity.2. The method of claim 1 , wherein the gratings comprise double patterned gratings.3. The method of claim 1 , wherein the parameter of the lithographic process comprises overlay.4. The method of claim 1 , wherein the ...

Alignment sensor, lithographic apparatus and alignment method

An alignment sensor including an illumination source, such as a white light source, having an illumination grating operable to diffract higher order radiation at an angle dependent on wavelength; and illumination optics to deliver the diffracted radiation onto an alignment grating from at least two opposite directions. For every component wavelength incident on the alignment grating, and for each direction, the zeroth diffraction order of radiation incident from one of the two opposite directions overlaps a higher diffraction order of radiation incident from the other direction. This optically amplifies the higher diffraction orders with the overlapping zeroth orders.

Method to determine a patterning process parameter

A method to determine a patterning process parameter, the method comprising: for a target, calculating a first value for an intermediate parameter from data obtained by illuminating the target with radiation comprising a central wavelength; for the target, calculating a second value for the intermediate parameter from data obtained by illuminating the target with radiation comprising two different central wavelengths; and calculating a combined measurement for the patterning process parameter based on the first and second values for the intermediate parameter.

Metrology in lithographic processes

An apparatus and method for estimating a parameter of a lithographic process and an apparatus and method for determining a relationship between a measure of quality of an estimate of a parameter of a lithographic process are provided. In the apparatus for estimating the parameter a processor is configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an inspection apparatus and associated method for measuring a target structure on a substrate. The inspection apparatus comprises an illumination source for generating measurement radiation; an optical arrangement for focusing the measurement radiation onto said target structure; and a compensatory optical device. The compensatory optical device may comprise an SLM operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in said optical arrangement. In alternative embodiments, the compensatory optical device may be located in the beam of measurement radiation, or in the beam of pump radiation used to generate high harmonic radiation in a HHG source. Where located in the beam of pump radiation, the compensatory optical device may be used to correct pointing errors, or impart a desired profile or varying illumination pattern in a beam of the measurement radiation.

Methods and apparatus for predicting performance of a measurement method, measurement method and apparatus

Methods of aligning a diffractive optical system and diffracting beams, diffractive optical element and apparatus

Metrology Method and Apparatus, Computer Program and Lithographic System

Disclosed is a method, and associated apparatuses, for measuring a parameter of interest relating to a structure having at least two layers. The method comprises illuminating the structure with measurement radiation and detecting scattered radiation having been scattered by said structure. The scattered radiation comprises normal and complementary higher diffraction orders. A scatterometry model which relates a scattered radiation parameter to at least a parameter of interest and an asymmetry model which relates the scattered radiation parameter to at least one asymmetry parameter are defined, the asymmetry parameter relating to one or more measurement system errors and/or an asymmetry in the target other than a misalignment between the two layers. A combination of the scatterometry model and asymmetry model is used to determine a system of equations, and the system of equations is then solved for the parameter of interest. 120-. (canceled)21. A method of measuring a parameter of interest relating to a structure having at least two layers , comprising:illuminating the structure with measurement radiation and detecting scattered radiation having been scattered by the structure, wherein the scattered radiation comprises normal and complementary higher diffraction orders; the scatterometry model relates a scattered radiation parameter to at least α parameter of interest; and', 'the asymmetry model relates the scattered radiation parameter to at least one asymmetry parameter, the at least one asymmetry parameter relating to one or more measurement system errors and/or an asymmetry in the target other than a misalignment between the two layers;, 'defining a scatterometry model and an asymmetry model relating to the structure, whereinusing a combination of the scatterometry model and asymmetry model to determine a system of equations, each equation of the system of equations relating to a different measurement value of a set of measurement values for the scattered ...

Inspection method and apparatus, substrates for use therein and device manufacturing method

A substrate is provided with device structures and metrology structures (800). The device structures include materials exhibiting inelastic scattering of excitation radiation of one or more wavelengths. The device structures include structures small enough in one or more dimensions that the characteristics of the inelastic scattering are influenced significantly by quantum confinement. The metrology structures (800) include device-like structures (800b) similar in composition and dimensions to the device features, and calibration structures (800a). The calibration structures are similar to the device features in composition but different in at least one dimension. Using an inspection apparatus and method implementing Raman spectroscopy, the dimensions of the device-like structures can be measured by comparing spectral features of radiation scattered inelastically from the device-like structure and the calibration structure.

Metrology parameter determination and metrology recipe selection

A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.

Alignment sensor and lithographic apparatus

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an illumination source for generating measurement radiation for an inspection apparatus. The source generates at least first measurement radiation and second measurement radiation such that the first measurement radiation and the second measurement radiation interfere to form combined measurement radiation modulated with a beat component. The illumination source may be a HHG source. Also disclosed is an inspection apparatus comprising such a source and an associated inspection method.

Method and apparatus for determining the property of a structure, device manufacturing method

A structure of interest (T) is irradiated with radiation for example in the x-ray or EUV waveband, and scattered radiation is detected by a detector (19, 274, 908, 1012). A processor (PU) calculates a property such as linewidth (CD) or overlay (OV), for example by simulating (S16) interaction of radiation with a structure and comparing (S17) the simulated interaction with the detected radiation. The method is modified (S14a, S15a, S19a) to take account of changes in the structure which are caused by the inspection radiation. These changes may be for example shrinkage of the material, or changes in its optical characteristics. The changes may be caused by inspection radiation in the current observation or in a previous observation.

Method and apparatus for generating illuminating radiation

An method for generating illuminating radiation in an illumination apparatus for use in an inspection apparatus for use in lithographic processes is described. A driving radiation beam is provided that comprises a plurality of radiation pulses. The beam is split into first and second pluralities of driving radiation pulses. Each plurality of driving radiation pulses has a controllable characteristic. The first and second pluralities may be used to generate an illuminating radiation beam with an output wavelength spectrum. The first and second controllable characteristics are controlled so as to control first and second portions respectively of the output wavelength spectrum of the illuminating radiation beam.

HHG source, inspection apparatus and method for performing a measurement

Disclosed is a method of performing a measurement in an inspection apparatus, and an associated inspection apparatus and HHG source. The method comprises configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control the output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; and illuminating a target structure with said illuminating radiation. The method may comprise configuring the driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks. Alternatively the method may comprise using a plurality of driving laser pulses of different wavelengths such that the output emission spectrum is substantially monochromatic.

Inspection apparatus for inspecting a substrate manufactured by a lithographic process, methods for inspecting structures formed by a lithographic process and manufacturing semiconductor devices, and computer program product

Lithographic apparatus alignment sensor and method

A lithographic apparatus comprises a substrate table constructed to hold a substrate; and a sensor configured to sense a position of an alignment mark provided onto the substrate held by the substrate table. The sensor comprises a source of radiation configured to illuminate the alignment mark with a radiation beam, a detector configured to detect the radiation beam, having interacted with the alignment mark, as an out of focus optical pattern, and a data processing system. The data processing system is configured to receive image data representing the out of focus optical pattern, and process the image data for determining alignment information, comprising applying a lensless imaging algorithm to the out of focus optical pattern.

Methods and Apparatus for Predicting Performance of a Measurement Method, Measurement Method and Apparatus

A metrology apparatus ( 302 ) includes a higher harmonic generation (HHG) radiation source for generating ( 310 ) EUV radiation. Operation of the HHG source is monitored using a wavefront sensor ( 420 ) which comprises an aperture array ( 424, 702 ) and an image sensor ( 426 ). A grating ( 706 ) disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings ( 706 ) of each subset having a different direction of dispersion. The spectrally resolved wavefront information ( 430 ) is used in feedback control ( 432 ) to stabilize operation of the HGG source, and/or to improve accuracy of metrology results.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes a sensor, such as an alignment sensor including a self-referencing interferometer, configured to determine the position of an alignment target comprising a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans the structure. Multiple position-dependent signals are detected and processed to obtain multiple candidate position measurements. An asymmetry sensor receives a share of positive and negative orders of radiation diffracted by the periodic structure to produce a measurement of asymmetry in the periodic structure. The asymmetry measurement is used to improve accuracy of the position read by the sensor. Additional information on asymmetry may be obtained by comparing the multiple position-dependent signals, and combined with asymmetry sensor results to improve accuracy further.

Inspection method and apparatus, substrates for use therein and device manufacturing method

A substrate is provided with device structures and metrology structures (800). The device structures include materials exhibiting inelastic scattering of excitation radiation of one or more wavelengths. The device structures include structures small enough in one or more dimensions that the characteristics of the inelastic scattering are influenced significantly by quantum confinement. The metrology structures (800) include device-like structures (800b) similar in composition and dimensions to the device features, and calibration structures (800a). The calibration structures are similar to the device features in composition but different in at least one dimension. Using an inspection apparatus and method implementing Raman spectroscopy, the dimensions of the device-like structures can be measured by comparing spectral features of radiation scattered inelastically from the device-like structure and the calibration structure.

Inspection apparatus and methods, substrates having metrology targets, lithographic system and device manufacturing method

Disclosed is an inspection apparatus for use in lithography. It comprises a support for a substrate carrying a plurality of metrology targets; an optical system for illuminating the targets under predetermined illumination conditions and for detecting predetermined portions of radiation diffracted by the targets under the illumination conditions; a processor arranged to calculate from said detected portions of diffracted radiation a measurement of asymmetry for a specific target; and a controller for causing the optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and calculate from the results of said asymmetry measurements a measurement of a performance parameter of the lithographic process for structures of said smaller size. Also disclosed are substrates provided with a plurality of novel metrology targets formed by a lithographic ...

Metrology Apparatus, Method of Measuring a Structure and Lithographic Apparatus

Disclosed is a metrology apparatus and method for measuring a structure formed on a substrate by a lithographic process. The metrology apparatus comprises an illumination system operable to provide measurement radiation comprising a plurality of wavelengths; and a hyperspectral imager operable to obtain a hyperspectral representation of a measurement scene comprising the structure, or a part thereof, from scattered measurement radiation subsequent to the measurement radiation being scattered by the structure.

Apparatus For Delivering Gas and Illumination Source for Generating High Harmonic Radiation

Disclosed is a high harmonic generation (HHG) radiation source which may be used to generate measurement radiation for an inspection apparatus. In such a radiation source, a pump radiation source is operable to emit pump radiation at a high harmonic generation gas medium thereby exciting the high harmonic generation gas medium within a pump radiation interaction region so as to generate the high harmonic radiation and an ionization radiation source is operable to emit ionization radiation at the high harmonic generation gas medium to ionize a gas at an ionization region between the pump radiation interaction region and an optical output of the illumination source. 1. An illumination source for generating high harmonic radiation , comprising:a pump radiation source operable to emit pump radiation at a high harmonic generation gas medium thereby exciting the high harmonic generation gas medium within a pump radiation interaction region so as to generate the high harmonic radiation; andan ionization radiation source operable to emit ionization radiation at the high harmonic generation gas medium to ionize a gas at an ionization region between the pump radiation interaction region and an optical output of the illumination source.2. The illumination source of claim 1 , wherein the ionization region is adjacent to the pump radiation interaction region.3. The illumination source of claim 1 , wherein the illumination source is arranged such that the ionization radiation ionizes the gas at the ionization region substantially simultaneously with the pump radiation exciting the high harmonic generation gas medium.4. The illumination source of claim 1 , wherein a propagation direction of the ionization radiation is opposite to a propagation direction of the pump radiation.5. The illumination source of claim 1 , wherein a propagation direction of the ionization radiation is orthogonal to a propagation direction of the pump radiation.6. The illumination source of claim 1 , ...

Metrology Apparatus, Lithographic System, And Method Of Measuring A Structure

A metrology apparatus is disclosed that measures a structure formed on a substrate to determine a parameter of interest. The apparatus comprises an optical system configured to focus radiation onto the structure and direct radiation after reflection from the structure onto a detector, wherein: the optical system is configured such that the detector detects a radiation intensity resulting from interference between radiation from at least two different points in a pupil plane field distribution, wherein the interference is such that a component of the detected radiation intensity containing information about the parameter of interest is enhanced relative to one or more other components of the detected radiation intensity. 115.-. (canceled)16. A metrology apparatus for measuring a structure formed on a substrate to determine a parameter of interest , the metrology apparatus comprising: the optical system is configured such that the detector detects a radiation intensity resulting from interference between radiation from at least two different points in a pupil plane field distribution,', 'the interference is such that a component of the detected radiation intensity containing information about the parameter of interest is enhanced relative to one or more other components of the detected radiation intensity., 'an optical system configured to focus radiation onto the structure and to direct radiation after reflection from the structure onto a detector, wherein17. The apparatus of claim 16 , wherein the optical system is configured to cause the detector to detect a plurality of radiation intensities resulting from interference between radiation from a corresponding plurality of pairs of points in a pupil plane field distribution claim 16 , each pair of points being positioned mirror symmetrically with respect to each other about the same line of mirror symmetry.18. The apparatus of claim 16 , wherein the optical system is configured to cause the detector to detect a ...

Method of performing a measurement in an inspection apparatus, inspection apparatus and computer program product

Methods of aligning a diffractive optical system and diffracting beams, diffractive optical element and apparatus

A method of aligning a diffractive optical system, to be operated with an operating beam, comprises: aligning (558) the diffractive optical system using an alignment beam having a different wavelength range from the operating beam and using a diffractive optical element optimized (552) to diffract the alignment beam and the operating beam in the same (or a predetermined) direction. In an example, the alignment beam comprises infra-red (IR) radiation and the operating beam comprises soft X-ray (SXR) radiation. The diffractive optical element is optimized by providing it with a first periodic structure with a first pitch (pIR) and a second periodic structure with a second pitch (pSXR). After alignment, the vacuum system is pumped down (562) and in operation the SXR operating beam is generated (564) by a high harmonic generation (HHG) optical source pumped by the IR alignment beam’ optical source.

Metrology in Lithographic Processes

An apparatus and method for estimating a parameter of a lithographic process and an apparatus and method for determining a relationship between a measure of quality of an estimate of a parameter of a lithographic process are provided. In the apparatus for estimating the parameter a processor is configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features. 115.-. (canceled)16. A lithographic apparatus comprising: 'a processor configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features.', 'an apparatus configured to estimate a parameter of a lithographic process that has been undertaken on a tested substrate, the estimation being based on regression analysis data that has been determined by a regression analysis of asymmetry intensity data that has, in turn, been determined using radiation emitted by an optical system at one or more wavelengths and diffracted by at least first features of the tested substrate, the apparatus comprising17. An apparatus for ...

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Metrology apparatus, lithographic system, and method of measuring a structure

Polarization independent interferometer

Apparatus, systems, and methods are used for detecting the alignment of a feature on a substrate using a polarization independent interferometer. The apparatus, system, and methods include optical elements that receive light that has diffracted or scattered from a mark on a substrate. The optical elements may split the diffracted light into multiple subbeams of light which are detected by one or more detectors. The diffracted light may be combined optically or during processing after detection. The system may determine alignment and/or overlay based on the received diffracted light having any polarization angle or state.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Metrology in lithographic processes

Level sensor arrangement for lithographic apparatus, lithographic apparatus and device manufacturing method

HHG source, inspection apparatus and method for performing a measurement

Disclosed is a method of performing a measurement in an inspection apparatus, and an associated inspection apparatus and HHG source. The method comprises configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control the output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; and illuminating a target structure with said illuminating radiation. The method may comprise configuring the driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks. Alternatively the method may comprise using a plurality of driving laser pulses of different wavelengths such that the output emission spectrum is substantially monochromatic.

Methods and apparatus for predicting performance of a measurement method, measurement method and apparatus

Target structures such as overlay gratings (Ta and Tb) are formed on a substrate (W) by a lithographic process. The first target is illuminated with a spot of first radiation (456a, Sa) and simultaneously the second target is illuminated with a spot of second radiation (456b, Sb). A sensor (418) detects at different locations, portions (460x-, 460x+) of said first radiation that have been diffracted in a first direction by features of the first target and portions (460y-, 460y+) of said second radiation that have been diffracted in a second direction by features of the second target. Asymmetry in X and Y directions can be detected simultaneously, reducing the time required for overlay measurements in X and Y. The two spots of radiation at soft x-ray wavelength can be generated simply by exciting two locations (710a, 710b) in a higher harmonic generation (HHG) radiation source or inverse Compton scattering source.

Metrology apparatus, lithographic system, and method of measuring a structure

A metrology apparatus is disclosed that measures a structure formed on a substrate to determine a parameter of interest. The apparatus comprises an optical system configured to focus radiation onto the structure and direct radiation after reflection from the structure onto a detector, wherein: the optical system is configured such that the detector detects a radiation intensity resulting from interference between radiation from at least two different points in a pupil plane field distribution, wherein the interference is such that a component of the detected radiation intensity containing information about the parameter of interest is enhanced relative to one or more other components of the detected radiation intensity.

ALIGNMENT SENSOR FOR LITHOGRAPHIC APPARATUS

A lithographic apparatus includes an alignment sensor configured to determine the position of an alignment target having a periodic structure. The alignment sensor includes a demultiplexer to demultiplex a number of intensity channels. The demultiplexer includes a number of stages arranged in series and a number of demultiplexing components, each demultiplexing component operable to divide an input radiation beam into two radiation beam portions. The first stage has a first demultiplexing component that is arranged to receive as an input radiation beam an incident radiation beam. Each successive stage is arranged such that it has twice the number of demultiplexing components as a preceding stage, each demultiplexing component of each stage after the first stage receiving as an input one of the radiation beam portions output from a demultiplexing component of the preceding stage. 1. An alignment sensor system comprising:an apparatus configured to demultiplex an incident radiation beam comprising a first wavelength band, the apparatus comprising:a plurality of stages arranged in series, the plurality of stages comprising a first stage and one or more subsequent stages; anda plurality of demultiplexing components, each demultiplexing component operable to divide an input radiation beam into two radiation beam portions, wherein:the first stage comprises a first demultiplexing component arranged to receive, as an input radiation beam, the incident radiation beam, andthe plurality of demultiplexing components are arranged such that each successive stage comprises twice the number of demultiplexing components as a preceding stage, each demultiplexing component of each stage after the first stage receiving as an input one of the radiation beam portions output from a demultiplexing component of the preceding stage.2. The alignment sensor system according to claim 1 , wherein each demultiplexing component comprises a dichroic filter.3. The alignment sensor system according to ...

Alignment sensor for lithographic apparatus

A lithographic apparatus includes an alignment sensor configured to determine the position of an alignment target having a periodic structure. The alignment sensor includes a demultiplexer to demultiplex a number of intensity channels. The demultiplexer includes a number of stages arranged in series and a number of demultiplexing components, each demultiplexing component operable to divide an input radiation beam into two radiation beam portions. The first stage has a first demultiplexing component that is arranged to receive as an input radiation beam an incident radiation beam. Each successive stage is arranged such that it has twice the number of demultiplexing components as a preceding stage, each demultiplexing component of each stage after the first stage receiving as an input one of the radiation beam portions output from a demultiplexing component of the preceding stage.

Alignment system, lithographic apparatus and method of determining the position of an alignment mark

Method and apparatus for generating illuminating radiation

An method for generating illuminating radiation in an illumination apparatus for use in an inspection apparatus for use in lithographic processes is described. A driving radiation beam is provided that comprises a plurality of radiation pulses. The beam is split into first and second pluralities of driving radiation pulses. Each plurality of driving radiation pulses has a controllable characteristic. The first and second pluralities may be used to generate an illuminating radiation beam with an output wavelength spectrum. The first and second controllable characteristics are controlled so as to control first and second portions respectively of the output wavelength spectrum of the illuminating radiation beam.

Mark position determination method

A method of determining positions of marks, the marks comprising periodic structures, at least some of the structures comprising periodic sub-structures, the sub-structures having a smaller period than the structures, the marks formed with positional offsets between the sub-structures and structures, the positional offsets caused by a combination of both known and unknown components, the method comprising illuminating a plurality of the marks with radiation having different characteristics, detecting radiation diffracted by the marks using one or more detectors which produce output signals, discriminating between constituent parts of the signals, the discriminating based on a variation of the signals as a function of spatial positions of the marks on a substrate, selecting at least one of the constituent parts of the signals, and using the at least one selected constituent part, and information relating to differences between the known components, to calculate a corrected position of at least one mark.

Metrology apparatus, method of measuring a structure and lithographic apparatus

Disclosed is a metrology apparatus and method for measuring a structure formed on a substrate by a lithographic process. The metrology apparatus comprises an illumination system operable to provide measurement radiation comprising a plurality of wavelengths; and a hyperspectral imager operable to obtain a hyperspectral representation of a measurement scene comprising the structure, or a part thereof, from scattered measurement radiation subsequent to the measurement radiation being scattered by the structure.

Apparatus For Delivering Gas and Illumination Source for Generating High Harmonic Radiation

Disclosed is gas delivery system which is suitable for a high harmonic generation (HHG) radiation source which may be used to generate measurement radiation for an inspection apparatus. In such a radiation source, a gas delivery element delivers gas in a first direction. The gas delivery element has an optical input and an optical input, defining an optical path running in a second direction. The first direction is arranged relative to the second direction at an angle that is not perpendicular or parallel. Also disclosed is a gas delivery element having a gas jet shaping device, or a pair of gas delivery elements, one of which delivers a second gas, such that the gas jet shaping device or second gas is operable to modify a flow profile of the gas such that the number density of the gas falls sharply. 1. A gas delivery system for use in an illumination source , comprising a gas delivery element arranged to direct gas in at least a first direction , wherein the gas delivery element comprises:an optical input; andan optical output,wherein the input and the output define an optical path, the optical path being oriented in a second direction, andwherein the second direction is non-perpendicular and non-parallel to the first direction.2. A gas delivery system according to claim 1 , wherein the first direction is at an obtuse angle relative to the second direction.3. A gas delivery system according to or claim 1 , wherein the optical input and optical output are arranged to allow pump radiation to pass through the gas to generate high harmonic radiation.4. A gas delivery system according to claim 3 , wherein the optical input and optical input are arranged concentrically with the optical path.5. A gas delivery system according to or claim 3 , wherein the optical input comprises an opening in a first wall of the gas delivery system claim 3 , and wherein the optical output comprises an opening in an opposing wall of the gas delivery system.6. A gas delivery system according ...

Mark position measuring apparatus and method, lithographic apparatus and device manufacturing method

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an illumination source apparatus comprising a high harmonic generation medium, a pump radiation source and a spatial filter. The pump radiation source emits a beam of pump radiation having a profile comprising no pump radiation in a central region of the beam and excites the high harmonic generation medium so as to generate high harmonic radiation. The pump radiation and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation. The spatial filter is located beyond a focal plane of the beam of pump radiation, and blocks the pump radiation. Also disclosed is a method of generating high harmonic measurement radiation optimized for filtration of pump radiation therefrom.

Alignment system

An alignment system, method and lithographic apparatus are provided for determining the position of an alignment mark, the alignment system comprising a first system configured to produce two overlapping images of the alignment mark that are rotated by around 180 degrees with respect to one another, and a second system configured to determine the position of the alignment mark from a spatial distribution of an intensity of the two overlapping images.

Methods and patterning devices and apparatuses for measuring focus performance of a lithographic apparatus, device manufacturing method

A lithographic apparatus (LA) prints product features and at least one focus metrology pattern (T) on a substrate. The focus metrology pattern is defined by a reflective reticle and printing is performed using EUV radiation (404) incident at an oblique angle ([theta]). The focus metrology pattern comprises a periodic array of groups of first features (422). A spacing (S1) between adjacent groups of first features is much greater than a dimension (CD) of the first features within each group. Due to the oblique illumination, the printed first features become distorted and/or displaced as a function of focus error. Second features 424 may be provided as a reference against which displacement of the first features may be seen. Measurement of this distortion and/or displacement may be by measuring asymmetry as a property of the printed pattern. Measurement can be done at longer wavelengths, for example in the range 350-800 nm.

Metrology method for a lithographic apparatus

Alignment sensor for lithographic apparatus

A lithographic apparatus includes an alignment sensor configured to determine the position of an alignment target comprising a periodic structure. The alignment sensor includes a demultiplexer to demultiplex a number of intensity channels. The demultiplexer includes a number of stages arranged in series and a number of demultiplexing components, each demultiplexing component being operable to divide an input radiation beam into two radiation beam portions. The first stage has a first demultiplexing component that is arranged to receive as an input radiation beam an incident radiation beam. Each successive stage is arranged such that it has twice the number of demultiplexing components as a preceding stage, each demultiplexing component of each stage after the first stage receiving as an input one of the radiation beam portions output from a demultiplexing component of the preceding stage.

Method and system for determining information about a target structure

Methods and systems for determining information about a target structure are disclosed. In one arrangement, a value of an asymmetry indicator for the target structure is obtained. The value of the asymmetry indicator represents an amount of an overlay independent asymmetry in the target structure. An error in an initial overlay measurement performed on the target structure at a previous time is estimated. The estimation is performed using the obtained value of the asymmetry indicator and a relationship between values of the asymmetry indicator and overlay measurement errors caused at least partially by overlay independent asymmetries. An overlay in the target structure is determined using the initial overlay measurement and the estimated error.

Mark position measuring apparatus and method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an illumination arrangement to direct radiation across a pupil of the apparatus, the illumination arrangement comprising an illumination source to provide multiple-wavelength radiation of substantially equal polarization and a wave plate to alter the polarization of the radiation in dependency of the wavelength, such that radiation of different polarization is supplied; an objective lens to direct radiation on the mark using the radiation supplied by the illumination arrangement while scanning the radiation across the mark in a scanning direction; a radiation processing element to process radiation that is diffracted by the mark and received by the objective lens; and a detection arrangement to detect variation in an intensity of radiation output by the radiation processing element during the scanning and to calculate from the detected variation a position of the mark in at least a first direction of measurement.

Apparatus for delivering gas and illumination source for generating high harmonic radiation

METROLOGY METHOD AND APPARATUS AND COMPUTER PROGRAM

Apparatus for delivering gas and illumination source for generating high harmonic radiation

Disclosed is gas delivery system which is suitable for a high harmonic generation (HHG) radiation source which may be used to generate measurement radiation for an inspection apparatus. In such a radiation source, a gas delivery element delivers gas in a first direction. The gas delivery element has an optical input and an optical output, defining an optical path running in a second direction. The first direction is arranged relative to the second direction at an angle that is not perpendicular or parallel. Also disclosed is a gas delivery element having a gas jet shaping device, or a pair of gas delivery elements, one of which delivers a second gas, such that the gas jet shaping device or second gas is operable to modify a flow profile of the gas such that the number density of the gas falls sharply.

Lithographic apparatus, lithographic alignment method, data processing system, and control software for being executed by the data processing system

Level Sensor Arrangement for Lithographic Apparatus, Lithographic Apparatus and Device Manufacturing Method

Disclosed is a method of measuring a position of at least one substantially reflective layer surface on a substrate in a lithographic apparatus, and associated level sensor and lithographic apparatuses. The method comprises performing at least two interferometrical measurements using a broadband light source. Between each measurement, the component wavelengths and/or intensity levels over the component wavelengths of the broadband source beam is varied such that, where it is only the intensity levels that are varied, the intensity variation is different for at least some of the beam's component wavelengths. Alternatively, a single measurement and subsequent processing of the measurement to obtain measurement data whereby the component wavelengths and/or intensity levels over the component wavelengths are different can be applied as well to obtain the position. 1. A method of measuring a position of at least one substantially reflective layer surface on a substrate in a lithographic apparatus , the method comprising performing , at least twice:a) separating a broadband source beam of radiation into a reference beam and a measurement beam by respectively reflecting part of the broadband source beam off a partly transparent optical element and passing part of the broadband source beam through the party transparent optical element;b) reflecting the measurement beam off the substrate to obtain a reflected measurement beam and reflecting the reference beam off a reflective surface to obtain a reflected reference beam;c) combining the reflected measurement beam and the reflected reference beam; andd) detecting at least two different interference patterns of the combined beams,wherein the different interference patterns are based on combined beams having at least one of different component wavelengths and intensity levels over the component wavelengths, such that, where it is only the intensity levels that are varied, said intensity variation is different for at least some ...

METROLOGY PARAMETER DETERMINATION AND METROLOGY RECIPE SELECTION

A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold. 1. A method comprising:for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data comprising signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement;determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; andidentifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.2. The method of claim 1 , comprising determining the fitted curve or function and wherein the curve or function is linear.3. The method of claim 1 , wherein the parameter is a statistical measure of spread.4. The method of claim 1 , wherein the identifying comprises determining a statistic claim 1 , fitted curve or ...

Illumination Source for an Inspection Apparatus, Inspection Apparatus and Inspection Method

Disclosed is an illumination source for generating measurement radiation for an inspection apparatus. The source generates at least first measurement radiation and second measurement radiation such that the first measurement radiation and the second measurement radiation interfere to form combined measurement radiation modulated with a beat component. The illumination source may be a HHG source. Also disclosed is an inspection apparatus comprising such a source and an associated inspection method. 153.-. (canceled)54. An illumination source for generating measurement radiation for an inspection apparatus , configured to generate at least first measurement radiation and second measurement radiation such that said first measurement radiation and said second measurement radiation interfere to form combined measurement radiation modulated with a beat component , wherein said illumination source is a high harmonic generation source.55. The illumination source of claim 54 , wherein said first measurement radiation and said second measurement radiation are spectrally coherent.56. The illumination source of claim 54 , wherein the first measurement radiation is centered on a first wavelength and the second measurement radiation comprises at least one component centered on a second wavelength.57. The illumination source of claim 56 , wherein the difference between said first wavelength and said second wavelength is smaller than 0.01 nm.58. The illumination source of claim 54 , wherein the frequency difference between the frequency of the first measurement radiation and the frequency of the second measurement radiation is less than 10 MHz claim 54 , or less than 100 kHz claim 54 , or less than 1 kHz.59. The illumination source of claim 54 , wherein each high harmonic of the first measurement radiation and a corresponding harmonic of the second measurement radiation interfere to form said combined measurement radiation modulated with a beat component.60. The illumination source ...

METROLOGY SENSOR FOR POSITION METROLOGY

Disclosed is a metrology device () configured to produce measurement illumination comprising a plurality of illumination beams, each of said illumination beams being spatially incoherent or pseudo-spatially incoherent and comprising multiple pupil points in an illumination pupil of the metrology device. Each pupil point in each one of said plurality of illumination beams has a corresponding pupil point in at least one of the other illumination beams of said plurality of illumination beams thereby defining multiple sets of corresponding pupil points, and the pupil points of each set of corresponding pupil points are spatially coherent with respect to each other. 162.-. (canceled)63. A metrology device configured to produce measurement illumination comprising:a plurality of illumination beams, each of the illumination beams being spatially incoherent or pseudo-spatially incoherent and comprising multiple pupil points in an illumination pupil of the metrology device,wherein each pupil point in each one of the plurality of illumination beams has a corresponding pupil point in at least one of the other illumination beams of the plurality of illumination beams thereby defining multiple sets of corresponding pupil points, andwherein the pupil points of each set of corresponding pupil points are spatially coherent with respect to each other.64. The metrology device of claim 63 , wherein each pupil point is substantially spatially incoherent with respect to all other pupil points in the same illumination beam.65. The metrology device of claim 63 , wherein each set of pupil points is a geometric translation of all other sets of pupil points within the illumination pupil claim 63 , at least for the illumination beams corresponding to a considered measurement direction.66. The metrology device of claim 63 , comprising an off-axis illumination generator to generate the plurality of illumination beams of measurement illumination from a single beam of incoherent radiation.67. The ...

Metrology Method and Apparatus and Computer Program

Disclosed are a method, computer program and a metrology apparatus for measuring a process effect parameter relating to a manufacturing process for manufacturing integrated circuits on a substrate. The method comprises determining for a structure, a first quality metric value for a quality metric from a plurality of measurement values each relating to a different measurement condition while cancelling or mitigating for the effect of the process effect parameter on the plurality of measurement values and a second quality metric value for the quality metric from at least one measurement value relating to at least one measurement condition without cancelling or mitigating for the effect of the process effect parameter on the at least one measurement value. The process effect parameter value for the process effect parameter can then be calculated from the first quality metric value and the second quality metric value, for example by calculating their difference. 115.-. (canceled)16. A method of measuring a process effect parameter relating to a manufacturing process for manufacturing integrated circuits on a substrate , the method comprising:determining for a structure, at least one first quality metric value for a quality metric from a set of measurement values relating to at least a first set of measurement conditions, such that each measurement value relates to a different measurement condition;determining for the structure, a second quality metric value for the quality metric from at least one measurement value relating to at least one measurement condition; andcalculating a process effect parameter value for the process effect parameter using the first quality metric value and the second quality metric value,wherein the calculated process effect parameter value is used to adjust a parameter of the measuring method or the manufacturing process.17. The method of claim 16 , wherein the step of calculating a process effect parameter value comprises calculating the ...

METHOD FOR OVERLAY METROLOGY AND APPARATUS THEREOF

A method includes receiving an image formed in a metrology apparatus wherein the image comprises at least the resulting effect of at least two diffraction orders, and processing the image wherein the processing comprises at least a filtering step, for example a Fourier filter. The process of applying a filter may be obtained also by placing an aperture in the detection branch of the metrology apparatus. 14.-. (canceled)5. A method comprising:receiving an image formed in a metrology apparatus, wherein the image comprises at least a resulting effect of at least two diffraction orders, andprocessing the image, wherein the processing comprises at least a filtering step.6. The method of claim 5 , wherein:the filtering step comprises a digital filtering.7. An aperture for a metrology apparatus comprising:an element comprising a radiation transmissive portion wherein the radiation transmissive portion transmits a single diffraction order.8. A metrology apparatus comprising:an aperture positioned in a detection branch of the metrology apparatus, wherein the aperture comprises an element with a radiation transmissive portion and wherein the radiation transmissive portion transmits a single diffraction order.9. The method of claim 5 , wherein the receiving the image comprises receiving the image in an image plane where a sensor is disposed.10. The method of claim 6 , wherein the filtering step comprises using a Fourier filer to obtain low frequency components of the image.11. The method of claim 10 , wherein the Fourier filter is applied to a synthetic image obtained as a difference between the images formed by positive and negative diffraction orders.12. The method of claim 10 , wherein an alignment step is performed between images obtained from negative and positive diffraction orders claim 10 , and before an asymmetry image is obtained as a difference between the image formed by the negative and positive diffraction orders.13. The method of claim 5 , further comprising ...

METROLOGY METHOD

A method provides the steps of receiving an image from a metrology tool, determining individual units of said image and discriminating the units which provide accurate metrology values. The images are obtained by measuring the metrology target at multiple wavelengths. The discrimination between the units, when these units are pixels in said image, is based on calculating a degree of similarity between said units. 18-. (canceled)9. A method comprising:receiving an image from a metrology tool,determining individual units of the image; anddiscriminating the units which provide accurate metrology values.10. The method of claim 9 , wherein the determining individual units comprises determining individual pixels.11. The method of claim 9 , wherein individual units of the image are pixels claim 9 , and the discriminating the units is based on comparing intensity values of each pixel with the intensity values of other pixels.12. The method of claim 9 , wherein the image is obtained by measuring a metrology target with multiple wavelengths and recording a scattered radiation from the metrology target.13. The method of claim 10 , wherein discriminating the units is based on finding linear dependence between measured intensities for each pixel at multiple wavelengths.14. The method claim 9 , wherein the image from the metrology tool is the image obtained for a positive biased metrology target or the image obtained for a negative biased metrology target.15. The method according of claim 9 , wherein the image is measured in a pre-lithography step.16. A method of selecting a region of interest in an image comprising:measuring the image of a metrology target by illuminating the metrology target with radiation;determining individual units of the image;discriminating the individual units of the image; andselecting pixels that form the region of interest, wherein the selected pixels have a degree of similarity as determined in the discriminating step.17. The method of claim 16 , ...

Inspection Apparatus, Inspection Method And Manufacturing Method

Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation () diffracted by from said target area interferes with reference radiation () interferes with to form an interference pattern at an image detector (). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image () of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (′) of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry. 1. An inspection apparatus for measuring properties of a target structure , the apparatus comprising:a radiation source; and an illumination path for receiving radiation from the radiation source, forming a beam of spatially coherent illuminating radiation and delivering said illuminating radiation onto a target area on a substrate;', 'a collection path for collecting at least a portion of non-zero order scattered radiation from said target area and delivering the collected scattered radiation to the image detector; and', 'a reference path for delivering reference radiation to the image detector,, 'and an image detector in combination with an optical system, the optical system defining the following beam pathswherein the reference radiation is coherent with the scattered radiation so as to interfere with the scattered radiation and form an interference pattern at the image detector,wherein the image detector is configured to capture one or more images of said interference pattern, anda processor arranged ...

Illumination Source for an Inspection Apparatus, Inspection Apparatus and Inspection Method

Disclosed is an inspection apparatus and associated method for measuring a target structure on a substrate. The inspection apparatus comprises an illumination source for generating measurement radiation; an optical arrangement for focusing the measurement radiation onto said target structure; and a compensatory optical device. The compensatory optical device may comprise an SLM operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in said optical arrangement. In alternative embodiments, the compensatory optical device may be located in the beam of measurement radiation, or in the beam of pump radiation used to generate high harmonic radiation in a HHG source. Where located in in the beam of pump radiation, the compensatory optical device may be used to correct pointing errors, or impart a desired profile or varying illumination pattern in a beam of the measurement radiation. 127-. (canceled)28. An inspection apparatus for measuring a target structure on a substrate , comprising:an illumination source configured to generate measurement radiation;an optical arrangement configured to focus the measurement radiation onto the target structure, the optical arrangement comprising at least one optical element being arranged to receive the measurement radiation at a grazing incidence; anda compensatory optical device operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in the optical arrangement.29. The inspection apparatus of claim 28 , wherein the non-uniform manufacturing defect in the optical arrangement comprises a slope error of at least one of the at least one optical elements of the optical arrangement.30. The inspection apparatus of claim 28 , wherein the compensatory optical device comprises a spatial light modulation device.31. The inspection apparatus of claim 30 , wherein the spatial light modulation ...

ALIGNMENT SENSOR, LITHOGRAPHIC APPARATUS AND ALIGNMENT METHOD

An alignment sensor including an illumination source, such as a white light source, having an illumination grating operable to diffract higher order radiation at an angle dependent on wavelength; and illumination optics to deliver the diffracted radiation onto an alignment grating from at least two opposite directions. For every component wavelength incident on the alignment grating, and for each direction, the zeroth diffraction order of radiation incident from one of the two opposite directions overlaps a higher diffraction order of radiation incident from the other direction. This optically amplifies the higher diffraction orders with the overlapping zeroth orders. 1. An alignment sensor comprising:an illumination source comprising a diffractive illumination structure operable to diffract higher order radiation at an angle dependent on wavelength; and the zeroth diffraction order of radiation incident from a first of each pair of opposite azimuthal directions overlaps a higher diffraction order of radiation incident from a second of each pair of opposite azimuthal directions; and', 'the zeroth diffraction order of radiation incident from the second of each pair of opposite azimuthal directions overlaps a higher diffraction order of radiation incident from the first of each pair of opposite azimuthal directions, wherein said higher diffraction orders are optically amplified with the overlapping zeroth orders., 'illumination optics being operable to deliver said diffracted illumination radiation from said illumination source onto a point on a diffractive alignment structure from at least a pair of opposite azimuthal directions, wherein said alignment sensor is operable such that following diffraction of said illumination radiation by said diffractive alignment structure, and independent of the wavelength or wavelengths comprised in said illumination radiation2. An alignment sensor as claimed in wherein said illumination source is a multi-wavelength illumination ...

MARK POSITION DETERMINATION METHOD

A method of determining positions of marks, the marks comprising periodic structures, at least some of the structures comprising periodic sub-structures, the sub-structures having a smaller period than the structures, the marks formed with positional offsets between the sub-structures and structures, the positional offsets caused by a combination of both known and unknown components, the method comprising illuminating a plurality of the marks with radiation having different characteristics, detecting radiation diffracted by the marks using one or more detectors which produce output signals, discriminating between constituent parts of the signals, the discriminating based on a variation of the signals as a function of spatial positions of the marks on a substrate, selecting at least one of the constituent parts of the signals, and using the at least one selected constituent part, and information relating to differences between the known components, to calculate a corrected position of at least one mark. 1. A method of determining positions of marks on a substrate , the marks comprising structures arranged periodically in at least a first direction , at least some of the structures comprising periodic sub-structures , the sub-structures having a smaller period than the structures , the marks being formed with positional offsets between the sub-structures and the structures , the positional offsets being caused by a combination of both known and unknown components , the method comprising:illuminating a plurality of the marks with radiation;detecting radiation which is diffracted by the marks and which has different characteristics, using one or more detectors which produce output signals;processing the signals, wherein the processing comprises discriminating between constituent parts of the signals, the discriminating being based on a variation of the signals as a function of spatial positions of the marks on the substrate;selecting at least one of the constituent ...

Inspection Method and Apparatus, Substrates for use Therein and Device Manufacturing Method

A substrate is provided with device structures and metrology structures (). The device structures include materials exhibiting inelastic scattering of excitation radiation of one or more wavelengths. The device structures include structures small enough in one or more dimensions that the characteristics of the inelastic scattering are influenced significantly by quantum confinement. The metrology structures () include device-like structures () similar in composition and dimensions to the device features, and calibration structures (). The calibration structures are similar to the device features in composition but different in at least one dimension. Using an inspection apparatus and method implementing Raman spectroscopy, the dimensions of the device-like structures can be measured by comparing spectral features of radiation scattered inelastically from the device-like structure and the calibration structure. 1. A method of inspecting a target structure comprising the steps of:directing radiation with a first wavelength at the target structure;receiving radiation scattered by the target structure and forming a spectrum of the scattered radiation so as to distinguish one or more spectral components in the spectrum having wavelengths different from the first wavelength due to inelastic scattering by the target structure; andcalculating a dimensional characteristic of the target structure based on characteristics of the spectral components.24.-. (canceled)5. The method as claimed in claim 1 , wherein said illumination and receiving steps are performed through separate objective elements.6. The method as claimed in claim 5 , wherein at least part of said scattered radiation is received on a side of the target structure opposite to that of the illumination optics claim 5 , thereby to receive forward scattered radiation.7. The method as claimed in claim 6 , wherein another part of said scattered radiation is received on a side of the target structure the same as that of ...

Method to Determine a Patterning Process Parameter

A method to determine a patterning process parameter, the method comprising: for a target, calculating a first value for an intermediate parameter from data obtained by illuminating the target with radiation comprising a central wavelength; for the target, calculating a second value for the intermediate parameter from data obtained by illuminating the target with radiation comprising two different central wavelengths; and calculating a combined measurement for the patterning process parameter based on the first and second values for the intermediate parameter. 115.-. (canceled)16. A method to determine a patterning process parameter , the method comprising:illuminating a target with radiation comprising a central wavelength and detecting a first result;illuminating the target with radiation comprising two different central wavelengths and detecting a second result;calculating a first value for an intermediate parameter based on the first result;calculating a second value for the intermediate parameter based on the second result; andcalculating a combined measurement for the patterning process parameter based on the first and second values for the intermediate parameter.17. The method of claim 16 , wherein the combined measurement is determined according to a function that depends on a measure of structural asymmetry of features within a periodic structure in one or more of an upper layer of the target and a lower layer of the target.18. The method of claim 17 , wherein the function depends on the measure of structural asymmetry such that when the structural asymmetry is greater claim 17 , the second value has a greater influence on the combined measurement.19. The method of claim 17 , wherein the intermediate parameter is overlay claim 17 , and the measure of structural asymmetry is proportional to a difference between the first overlay value and the second overlay value.20. The method of claim 17 , wherein the measure of structural asymmetry is measured from a ...

SUBSTRATE EDGE DETECTION

A method including directing, by an optical system, an illumination beam to a surface of a substrate, providing relative motion between the directed illumination beam and the substrate until the directed illumination beam is illuminated on a grating underneath an edge or a notch of the substrate, diffracting, by the grating, at least a portion of the illumination beam, and detecting, by the detector, the diffracted illumination. 1. A method comprising:directing, by an optical system, an illumination beam to a surface of a substrate;providing relative motion between the directed illumination beam and the substrate until the directed illumination beam is illuminated on a grating underneath an edge or a notch of the substrate;diffracting, by the grating, at least a portion of the illumination beam; anddetecting, by a detector, the diffracted illumination.2. The method of claim 1 , further comprising determining a position of a boundary of the edge or the notch based on the detected diffracted illumination from the grating.3. The method of claim 1 , wherein the grating comprises a plurality of features claim 1 , each of the features being elongate in a direction transverse to a portion of the boundary claim 1 , or to a tangent of the portion of the boundary claim 1 , of the edge or notch underneath which the grating is located.4. The method of claim 1 , wherein the grating is a grating with features having a direction of elongation extending away claim 1 , at the portion of the edge or notch underneath which the grating is located claim 1 , from a central region of the substrate.5. The method of claim 1 , wherein a grating period of the grating is determined based on a numerical factor of a pupil stop claim 1 , a numerical factor of the optical system claim 1 , a wavelength of the illumination beam claim 1 , and a focal length of an objective.6. A method comprising:directing, by an optical system, an illumination beam to a surface of a substrate;providing relative ...

Metrology Sensor, Lithographic Apparatus and Method for Manufacturing Devices

Disclosed is a metrology sensor apparatus and associated method. The metrology sensor apparatus comprises an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state and an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark. The metrology mark comprises a main structure and changes, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to the polarization state of the second portion of the scattered radiation. The metrology sensor apparatus further comprises an optical filtering system which filters out the second portion of the scattered radiation based on its polarization state. 119.-. (canceled)20. A metrology sensor apparatus comprising:an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state;an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark, the metrology mark comprising a main structure and being operable to change, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to ...

Illumination and detection apparatus for a metrology apparatus

An illumination and detection apparatus for a metrology tool, and associated method. The apparatus includes an illumination arrangement operable to produce measurement illumination having a plurality of discrete wavelength bands and having a spectrum having no more than a single peak within each wavelength band. The detection arrangement includes a detection beamsplitter to split scattered radiation into a plurality of channels, each channel corresponding to a different one of the wavelength bands; and at least one detector for separate detection of each channel.

METHOD AND SYSTEM FOR DETERMINING INFORMATION ABOUT A TARGET STRUCTURE

Methods and systems for determining information about a target structure are disclosed. In one arrangement, a value of an asymmetry indicator for the target structure is obtained. The value of the asymmetry indicator represents an amount of an overlay independent asymmetry in the target structure. An error in an initial overlay measurement performed on the target structure at a previous time is estimated. The estimation is performed using the obtained value of the asymmetry indicator and a relationship between values of the asymmetry indicator and overlay measurement errors caused at least partially by overlay independent asymmetries. An overlay in the target structure is determined using the initial overlay measurement and the estimated error. 115.-. (canceled)16. A method of determining information about a target structure on a substrate , comprising:obtaining a value of an asymmetry indicator for the target structure, the value of the asymmetry indicator representing an amount of an overlay independent asymmetry in the target structure, the overlay independent asymmetry being an asymmetry that is not caused by overlay;estimating an error in an initial overlay measurement performed on the target structure at a previous time, the estimation being performed using the obtained value of the asymmetry indicator and a relationship between values of the asymmetry indicator and overlay measurement errors caused at least partially by overlay independent asymmetries; anddetermining overlay in the target structure using the initial overlay measurement and the estimated error.17. The method of claim 16 , wherein the value of the asymmetry indicator is obtained for the target structure using information about asymmetry in radiation scattered from the target structure at each of a set of wavelengths.18. The method of claim 17 , wherein the set of wavelengths is preselected by obtaining the relationship between values of the asymmetry indicator and overlay measurement errors for ...

Illumination Source for an Inspection Apparatus, Inspection Apparatus and Inspection Method

Disclosed is an illumination source apparatus comprising a high harmonic generation medium, a pump radiation source and a spatial filter. The pump radiation source emits a beam of pump radiation having a profile comprising no pump radiation in a central region of the beam and excites the high harmonic generation medium so as to generate high harmonic radiation. The pump radiation and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation The spatial filter is located beyond a focal plane of the beam of pump radiation, and blocks the pump radiation. Also disclosed is a method of generating high harmonic measurement radiation optimized for filtration of pump radiation therefrom. 126-. (canceled)27. An illumination source apparatus , comprising:a high harmonic generation medium;a pump radiation source operable to emit a beam of pump radiation having a profile comprising no pump radiation in a central region of the beam, the beam of pump radiation configured to excite the high harmonic generation medium so as to generate high harmonic radiation; anda spatial filter located beyond a focal plane of the beam of pump radiation and operable to block the pump radiation;wherein the pump radiation and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation.28. The illumination source apparatus of claim 27 , wherein the beam of pump radiation has a substantially symmetrical profile.29. The illumination source apparatus of claim 27 , wherein the beam of pump radiation has a substantially annular profile.30. The illumination source apparatus of claim 27 , wherein the spatial filter is located in a far field of the beam of pump radiation.31. The illumination source apparatus of claim 30 , wherein the beam of pump radiation in the far field has a similar profile as in a near field of the beam of pump radiation.32. The illumination source apparatus of claim 30 , ...

ALIGNMENT SYSTEM

An alignment system, method and lithographic apparatus are provided for determining the position of an alignment mark, the alignment system comprising a first system configured to produce two overlapping images of the alignment mark that are rotated by around 180 degrees with respect to one another, and a second system configured to determine the position of the alignment mark from a spatial distribution of an intensity of the two overlapping images. 120-. (canceled)21. An alignment system for determining the position of an alignment mark , the alignment system comprising:a first system configured to produce two overlapping images of the alignment mark that are rotated by around 180 degrees with respect to one another; anda second system configured to determine the position of the alignment mark from a spatial distribution of an intensity of the two overlapping images.22. The alignment system of claim 21 , wherein the first system comprises a non-coherent alignment radiation beam source configured to illuminate the alignment mark with an alignment radiation beam.23. The alignment system of claim 21 , wherein the first system comprises optics that are configured to overfill the alignment mark with an alignment radiation beam.24. The alignment system of claim 21 , wherein the first system comprises an imaging detector configured to detect the spatial distribution of the intensity of the two overlapping images of the alignment mark and provide an output signal indicative of the spatial distribution of the intensity of the two overlapping images of the alignment mark.25. The alignment system of claim 21 , wherein the second system comprises a processor configured to determine the position of the alignment mark by analyzing the spatial distribution of the intensity of the two overlapping images for a plurality of different positions of the alignment mark relative to the alignment system.26. The alignment system of claim 21 , wherein the first system comprises a plurality ...

Position Measurement with Illumination Profile having Regions Confined to Peripheral Portion of Pupil

An apparatus (AS) measures positions of marks () on a lithographic substrate (W). An illumination arrangement () provides off-axis radiation from at least first and second regions. The first and second source regions are diametrically opposite one another with respect to an optical axis (O) and are limited in angular extent. The regions may be small spots selected according to a direction of periodicity of a mark being measured, or larger segments. Radiation at a selected pair of source regions can be generated by supplying radiation at a single source feed position to a self-referencing interferometer. A modified half wave plate is positioned downstream of the interferometer, which can be used in the position measuring apparatus. The modified half wave plate has its fast axis in one part arranged at 45° to the fast axis in another part diametrically opposite. 1. An arrangement for producing off-axis radiation at first and second positions diametrically opposed to one another in a pupil of the arrangement , the radiation at the first and second positions being identical in polarization and coherence , the arrangement comprising:a radiation source configured to generate radiation of a predetermined polarization at a single off-axis position;a self-referencing interferometer configured to receive and split the radiation from the radiation source so as to generate the radiation at the first and second positions;an element configured to adjust a polarization of the radiation at a first one of the first and second positions after the radiation emerges from the interferometer to match the polarization at a second one of the first and second positions, the element comprising a half wave plate whose fast axis is oriented differently at the first and second positions.2. The arrangement of claim 1 , wherein the single off-axis position is movable among a plurality of off-axis source feed positions within an entrance pupil of the apparatus to provide a plurality of off-axis ...

HHG Source, Inspection Apparatus and Method for Performing a Measurement

Disclosed is a method of performing a measurement in an inspection apparatus; and an associated inspection apparatus and HHG source. The method comprises configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control the output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; and illuminating a target structure with said illuminating radiation. The method may comprise configuring the driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks. Alternatively the method may comprise using a plurality of driving laser pulses of different wavelengths such that the output emission spectrum is substantially monochromatic. 1. A method of performing a measurement in an inspection apparatus , comprises:configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source tocontrol an output emission spectrum of illumination radiation provided by the high harmonic generation radiation source, wherein the output emission spectrum of the illumination radiation comprises a plurality of discrete harmonic peaks, andcontrol a wavelength of at least one of the harmonic peaks;illuminating a target structure with the illumination radiation;detecting scattered radiation from the illuminating of the target structure; anddetermining a characteristic of a layer of the target structure from the scattered radiation.2. The method of claim 1 , wherein a bandwidth of each harmonic peak is smaller than 0.2 nm.3. The method of claim 1 , wherein the spectral separation between adjacent harmonic peaks is greater than the bandwidth of the harmonic peaks.4. The method of claim 1 , wherein the driving laser pulse is controlled to optimize the wavelength of at least one of the harmonics peaks for maximum measurement sensitivity of the target structure.5. ...

METHOD AND APPARATUS FOR MEASURING ASYMMETRY OF A MICROSTRUCTURE, POSITION MEASURING METHOD, POSITION MEASURING APPARATUS, LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD

A lithographic apparatus includes an alignment sensor including a self-referencing interferometer for reading the position of an alignment target comprising a periodic structure. An illumination optical system for focusing radiation into a spot on said structure. An asymmetry detection optical system receives a share of positive and negative orders of radiation diffracted by the periodic structure, and forms first and second images of said spot on first and second detectors respectively, wherein said negative order radiation is used to form the first image and said positive order radiation is used to form the second image. A processor for processing together signals from said first and second detectors representing intensities of said positive and negative orders to produce a measurement of asymmetry in the periodic structure. The asymmetry measurement can be used to improve accuracy of the position read by the alignment sensor. 1. An apparatus for method of measuring an asymmetry dependent parameter of a periodic structure on a substrate , the apparatus comprising:an illumination optical system for focusing radiation into a spot on said structure;first and second detectors of radiation;a detection optical system for receiving radiation diffracted by the periodic structure, including at the same time both positive and negative higher orders of diffracted radiation, and forming first and second images of said spot on first and second detectors respectively, wherein said negative order radiation is used to form the first image and said positive order radiation is used to form the second image; anda processor for processing together signals from said first and second detectors representing intensities of said positive and negative orders to produce a measurement of said asymmetry dependent parameter in the periodic structure.2. An apparatus as claimed in wherein said illumination optical system is operable in an on-axis illumination mode in which said spot is formed by ...

Position measuring apparatus, position measuring method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an objective lens to direct radiation on a mark using radiation supplied by an illumination arrangement; an optical arrangement to receive radiation diffracted and specularly reflected by the mark, wherein the optical arrangement is configured to provide a first image and a second image, the first image being formed by coherently adding specularly reflected radiation and positive diffraction order radiation and the second image being formed by coherently adding specularly reflected radiation and negative diffraction order radiation; and a detection arrangement to detect variation in an intensity of radiation of the first and second images and to calculate a position of the mark in a direction of measurement therefrom.

Polarization Independent Interferometer

Apparatus, systems, and methods are used for detecting the alignment of a feature on a substrate using a polarization independent interferometer. The apparatus, system, and methods include optical elements that receive light that has diffracted or scattered from a mark on a substrate. The optical elements may split the diffracted light into multiple subbeams of light which are detected by one or more detectors. The diffracted light may be combined optically or during processing after detection. The system may determine alignment and/or overlay based on the received diffracted light having any polarization angle or state. 1. A lithographic apparatus comprising:an illumination system configured to condition a radiation beam;a substrate table configured to hold a substrate, the substrate comprising a mark;a projection system configured to project the radiation beam onto the substrate; and an interferometeric sub-system located along the optical path and comprising a beam splitter configured to split the diffracted or scattered radiation beam to form the first and second beams, and', 'a detector sub-system configured to detect respective first and second alignment signals containing information on a position of the mark based on the first and second beams., 'an optical system configured to receive a diffracted or scattered radiation beam from the mark along an optical path passing through the optical system and to output first and second beams, the optical system comprising2. The lithographic apparatus of claim 1 , wherein the beam splitter comprises a substantially polarization-neutral beam splitter that does not significantly affect polarization of the diffracted or scattered radiation beam claim 1 , the substantially polarization-neutral beam splitter comprising:a first input configured to receive the diffracted or scattered radiation beam;a first output configured to output a first composite beam that comprises the first beam; anda second output configured to output ...

METHOD AND APPARATUS FOR MEASURING ASYMMETRY OF A MICROSTRUCTURE, POSITION MEASURING METHOD, POSITION MEASURING APPARATUS, LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD

A lithographic apparatus includes a sensor, such as an alignment sensor including a self-referencing interferometer, configured to determine the position of an alignment target including a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans the structure. Multiple position-dependent signals are detected and processed to obtain multiple candidate position measurements. Asymmetry of the structure is calculated by comparing the multiple position-dependent signals. The asymmetry measurement is used to improve accuracy of the position read by the sensor. Additional information on asymmetry may be obtained by an asymmetry sensor receiving a share of positive and negative orders of radiation diffracted by the periodic structure to produce a measurement of asymmetry in the periodic structure. 1. A method of measuring a property of a structure , the method comprising:illuminating the structure with radiation and detecting radiation diffracted by the structure using a detector;processing signals representing the diffracted radiation to obtain a plurality of results related to a position of the structure, each result having the same form but being influenced in a different way by a variation in the property; andcalculating a measurement of the property of the structure that is at least partially based on a difference observed among the plurality of results.2. The method of claim 1 , wherein the plurality of results includes results based on illumination and detection of radiation at different wavelengths.3. The method of claim 1 , wherein the plurality of results includes results based on illumination and detection of radiation at different polarizations.4. The method of claim 1 , wherein the plurality of results includes results based on different spatial frequencies within a position-dependent signal received by the detector.5. The method of claim 4 , wherein the structure has a form that is ...

MARK POSITION MEASURING APPARATUS AND METHOD, LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD

An apparatus to measure the position of a mark, the apparatus including an illumination arrangement to direct radiation across a pupil of the apparatus, the illumination arrangement including an illumination source to provide multiple-wavelength radiation of substantially equal polarization and a wave plate to alter the polarization of the radiation in dependency of the wavelength, such that radiation of different polarization is supplied; an objective to direct radiation on the mark using the radiation supplied by the illumination arrangement while scanning the radiation across the mark in a scanning direction; a radiation processing element to process radiation that is diffracted by the mark and received by the objective; and a detection arrangement to detect variation in an intensity of radiation output by the radiation processing element during the scanning and to calculate from the detected variation a position of the mark in at least a first direction of measurement. 1. An apparatus comprising:an illumination arrangement to direct radiation with an illumination profile across a pupil of the apparatus, the illumination arrangement comprising an illumination source to provide multiple-wavelength radiation of substantially equal polarization and a wave plate to alter the polarization of the radiation in dependency of the wavelength, such that radiation of different polarization is supplied;an objective lens to direct radiation on a mark using the radiation supplied by the illumination arrangement while scanning the radiation across the mark in a scanning direction;a radiation processing element to process radiation that is diffracted by the mark and received by the objective lens; anda detection arrangement to detect variation in an intensity of radiation output by the radiation processing element during the scanning and to calculate from the detected variation a position of the mark in at least a first direction of measurement.2. The apparatus according to claim ...

METHODS AND APPARATUS FOR PREDICTING PERFORMANCE OF A MEASUREMENT METHOD, MEASUREMENT METHOD AND APPARATUS

Target structures such as overlay gratings (Ta and Tb) are formed on a substrate (W) by a lithographic process. The first target is illuminated with a spot of first radiation (, Sa) and simultaneously the second target is illuminated with a spot of second radiation (, Sb). A sensor () detects at different locations, portions (+) of said first radiation that have been diffracted in a first direction by features of the first target and portions (+) of said second radiation that have been diffracted in a second direction by features of the second target. Asymmetry in X and Y directions can be detected simultaneously, reducing the time required for overlay measurements in X and Y. The two spots of radiation at soft x-ray wavelength can be generated simply by exciting two locations () in a higher harmonic generation (HHG) radiation source or inverse Compton scattering source. 126-. (canceled)27. An inspection apparatus comprising:an illumination system; anda detection system,wherein the illumination system includes a source arrangement configured to generate first radiation at a first source location in a radiation generation space and configured to simultaneously generate second radiation at a second source location in the same radiation generation space, the first radiation and the second radiation including wavelengths less than 100 nm,wherein an optical system of the illumination system is arranged to focus radiation from both the first source location and the second source location so as to illuminate a first target location with a spot of the first radiation while simultaneously illuminating a second target location with a spot of the second radiation, andwherein the detection system is arranged to detect, at one or more first detection locations, portions of the first radiation that have been diffracted in a first direction by a first target structure at the first target location and arranged to simultaneously detect, at one or more second detection locations, ...

Methods of Aligning a Diffractive Optical System and Diffracting Beams, Diffractive Optical Element and Apparatus

A method of aligning a diffractive optical system, to be operated with an operating beam, comprises: aligning (558) the diffractive optical system using an alignment beam having a different wavelength range from the operating beam and using a diffractive optical element optimized (552) to diffract the alignment beam and the operating beam in the same (or a predetermined) direction. In an example, the alignment beam comprises infra-red (IR) radiation and the operating beam comprises soft X-ray (SXR) radiation. The diffractive optical element is optimized by providing it with a first periodic structure with a first pitch (pIR) and a second periodic structure with a second pitch (pSXR). After alignment, the vacuum system is pumped down (562) and in operation the SXR operating beam is generated (564) by a high harmonic generation (HHG) optical source pumped by the IR alignment beam’ optical source.

Inspection Apparatus and Methods, Substrates Having Metrology Targets, Lithographic System and Device Manufacturing Method

Disclosed is an inspection apparatus for use in lithography. It comprises a support for a substrate carrying a plurality of metrology targets; an optical system for illuminating the targets under predetermined illumination conditions and for detecting predetermined portions of radiation diffracted by the targets under the illumination conditions; a processor arranged to calculate from said detected portions of diffracted radiation a measurement of asymmetry for a specific target; and a controller for causing the optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and calculate from the results of said asymmetry measurements a measurement of a performance parameter of the lithographic process for structures of said smaller size. Also disclosed are substrates provided with a plurality of novel metrology targets formed by a lithographic process. 1. A substrate provided with metrology targets formed by a lithographic process , each of the metrology targets comprising:structures arranged to repeat with a spatial period in at least a first direction,wherein the metrology targets include targets each of which comprises sub-structures of a size several times smaller than the spatial period,wherein each of the targets is formed with a positional offset between two interleaved populations of sub-structures that is a combination of both known and unknown components, the known components being different for different targets.2. The substrate of claim 1 , wherein two or more of the targets having different known offsets between the interleaved populations of sub-structures are formed in close proximity with one another so as to form a composite target claim 1 , while other such composite targets are distributed across the substrate.3. The substrate of claim 1 , wherein the lithographic process used to form the ...

Lithographic Apparatus Alignment Sensor and Method

A lithographic apparatus comprises comprise a substrate table constructed to hold a substrate; and a sensor configured to sense a position of an alignment mark provided onto the substrate held by the substrate table. The sensor comprises a source of radiation configured to illuminate the alignment mark with a radiation beam, a detector configured to detect the radiation beam, having interacted with the alignment mark, as an out of focus optical pattern, and a data processing system. The data processing system is configured to receive image data representing the out of focus optical pattern, and process the image data for determining alignment information, comprising applying a lensless imaging algorithm to the out of focus optical pattern. 1. A lithographic apparatus comprising:a substrate table constructed to hold a substrate; anda sensor configured to sense a position of an alignment mark provided onto the substrate held by the substrate table, a source of radiation configured to illuminate the alignment mark with a radiation beam,', 'a detector configured to detect the radiation beam, having interacted with the alignment mark, as an out of focus optical pattern, and', 'convert the received image data into data for digitally emulating an optical system to determine alignment information.', 'receive image data representing the out of focus optical pattern, and'}, 'a data processing system configured to], 'wherein the sensor comprises2. The lithographic apparatus of claim 1 , wherein:the sensor comprises an optical propagation path configured for propagating the radiation beam, having interacted with the alignment mark, to the detector, andthe optical propagation path is a lensless optical propagation path.3. The lithographic apparatus of claim 1 , wherein:the sensor comprises an optical propagation path configured for propagating the radiation beam, having interacted with the alignment mark, to the detector, andthe optical propagation path is a non-focusing optical ...

Position Measuring Apparatus, Position Measuring Method, Lithographic Apparatus and Device Manufacturing Method

An apparatus for measuring positions of marks on a substrate, includes an illumination arrangement for supplying radiation with a predetermined illumination profile across a pupil of the apparatus, an objective lens for forming a spot of radiation on a mark using radiation supplied by said illumination arrangement, a radiation processing element for processing radiation that is diffracted by the mark, a first detection arrangement for detecting variations in an intensity of radiation output by the radiation processing element and for calculating therefrom a position of the mark, an optical arrangement, a second detection arrangement, wherein the optical arrangement serves to direct diffracted radiation to the second detection arrangement, and wherein the second detection arrangement is configured to detect size and/or position variations in the radiation and to calculate therefrom a defocus and/or local tilt of the mark. 1. An apparatus for measuring positions of marks on a substrate , the apparatus comprising:an illumination arrangement configured to supply radiation with a predetermined illumination profile across a pupil of the apparatus;an objective lens configured to form a spot of radiation on a mark using radiation supplied by said illumination arrangement while scanning said spot of radiation across the mark in a scanning direction;a radiation processing element configured to process radiation that is diffracted by the mark and received by said objective lens;a first detection arrangement configured to detect variations in an intensity of radiation output by the radiation processing element during said scanning and to calculate from the detected variations a position of the mark in at least a first direction of measurement;an optical arrangement; anda second detection arrangement;wherein the optical arrangement is configured to direct radiation that is diffracted by the mark to the second detection arrangement,and wherein the second detection arrangement is ...

Inspection Apparatus and Methods, Substrates Having Metrology Targets, Lithographic System and Device Manufacturing Method

Disclosed is an inspection apparatus for use in lithography. It comprises a support for a substrate carrying a plurality of metrology targets; an optical system for illuminating the targets under predetermined illumination conditions and for detecting predetermined portions of radiation diffracted by the targets under the illumination conditions; a processor arranged to calculate from said detected portions of diffracted radiation a measurement of asymmetry for a specific target; and a controller for causing the optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and calculate from the results of said asymmetry measurements a measurement of a performance parameter of the lithographic process for structures of said smaller size. Also disclosed are substrates provided with a plurality of novel metrology targets formed by a lithographic process. 1. An inspection apparatus for measuring a property of a lithographic process , the apparatus comprising:a support configured to support a substrate, the substrate carrying a plurality of metrology targets comprising structures formed by the lithographic process;an optical system configured to illuminate the plurality of targets under predetermined illumination conditions and to detect predetermined portions of radiation diffracted by the targets under said illumination conditions;a processor arranged to calculate, from said detected portions of diffracted radiation, a measurement of asymmetry for a specific target; anda controller configured to cause said optical system and processor to measure asymmetry in at least two of said targets which have different known components of positional offset between structures and smaller sub-structures within a layer on the substrate and to calculate from the results of said asymmetry measurements a measurement of a ...

Method and Apparatus for Determining the Property of a Structure, Device Manufacturing Method

A structure of interest (T) is irradiated with radiation for example in the x-ray or EUV waveband, and scattered radiation is detected by a detector (). A processor (PU) calculates a property such as linewidth (CD) or overlay (OV), for example by simulating (S) interaction of radiation with a structure and comparing (S) the simulated interaction with the detected radiation. The method is modified (S, S, S) to take account of changes in the structure which are caused by the inspection radiation. These changes may be for example shrinkage of the material, or changes in its optical characteristics. The changes may be caused by inspection radiation in the current observation or in a previous observation. 122-. (canceled)23. A method comprising:defining one or more variable parameters to represent a structure, the variable parameters including at least one parameter of interest;receiving observation data obtained by exposing the structure one or more times with inspection radiation and observing the inspection radiation after interaction with the structure; andbased on the observation data, determining a value for the parameter of interest as a property of the structure,wherein the determination of the parameter of interest is performed taking into account changes in the structure caused by the inspection radiation during an exposure period.24. The method of claim 23 , wherein the variable parameters include one or more time-related parameters representing the changes in the structure caused by the inspection radiation during the exposure period.25. The method of wherein the determining further includes determining a value for one or more of the time-related parameters.26. The method of claim 24 , wherein at least one of the time-related parameters represents a dimensional change caused by the inspection radiation in a part of the structure.27. The method of claim 24 , wherein at least one of the time-related parameters represents a change of an optical property caused ...

HHG Source, Inspection Apparatus and Method for Performing a Measurement

Disclosed is a method of performing a measurement in an inspection apparatus, and an associated inspection apparatus and HHG source. The method comprises configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control the output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; and illuminating a target structure with said illuminating radiation. The method may comprise configuring the driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks. Alternatively the method may comprise using a plurality of driving laser pulses of different wavelengths such that the output emission spectrum is substantially monochromatic. 158-. (canceled)59. A method of performing a measurement in an inspection apparatus , comprises:configuring one or more controllable characteristics of at least one driving laser pulse of a high harmonic generation radiation source to control an output emission spectrum of illumination radiation provided by the high harmonic generation radiation source; andilluminating a target structure with the illuminating radiation.60. The method of claim 59 , wherein the configuring step comprises configuring one or more controllable characteristics of a driving laser pulse so that the output emission spectrum comprises a plurality of discrete harmonic peaks.61. The method of claim 60 , wherein a bandwidth of each harmonic peak is smaller than 0.2 nm.62. The method of claim 60 , wherein the spectral separation between adjacent harmonic peaks is greater than the bandwidth of the harmonic peaks.63. The method of claim 60 , wherein the configuring step comprises configuring a central wavelength of the driving laser pulse so as to control the wavelength of at least one of the harmonic peaks.64. The method of claim 60 , wherein the configuring step comprises configuring a central wavelength ...

Method and Apparatus for Generating Illuminating Radiation

An method for generating illuminating radiation in an illumination apparatus for use in an inspection apparatus for use in lithographic processes is described. A driving radiation beam is provided that comprises a plurality of radiation pulses. The beam is split into first and second pluralities of driving radiation pulses. Each plurality of driving radiation pulses has a controllable characteristic. The first and second pluralities may be used to generate an illuminating radiation beam with an output wavelength spectrum. The first and second controllable characteristics are controlled so as to control first and second portions respectively of the output wavelength spectrum of the illuminating radiation beam.

METHOD AND APPARATUS FOR MEASURING ASYMMETRY OF A MICROSTRUCTURE, POSITION MEASURING METHOD, POSITION MEASURING APPARATUS, LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD

A lithographic apparatus includes an alignment sensor including a self-referencing interferometer for reading the position of a mark including a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans said structure. Multiple position-dependent signals are detected in a detection optical system and processed to obtain multiple candidate position measurements. Each mark includes sub-structures of a size smaller than a resolution of the optical system. Each mark is formed with a positional offset between the sub-structures and larger structures that is a combination of both known and unknown components. A measured position of at least one mark is calculated using signals from a pair of marks, together with information on differences between the known offsets, in order to correct for said unknown component of said positional offset. 1. A method of measuring positions of marks on a substrate using an optical system , each mark comprising structures arranged periodically in at least a first direction , at least some of said structures comprising smaller sub-structures , each mark being formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components , the method comprising:(a) illuminating each mark with radiation and detecting radiation diffracted by said structure using one or more detectors to obtain signals containing information on the position of the mark;(b) processing said signals to calculate a measured position of at least one mark, the calculation using signals from a plurality of marks, together with information on differences between the known offsets of said marks, in order to correct for said unknown component of said positional offset.2. A method as claimed in wherein in step (a) a plurality of signals containing position information are obtained for each mark claim 1 , each signal having the same form but ...

Methods and Apparatus for Predicting Performance of a Measurement Method, Measurement Method and Apparatus

A metrology apparatus () includes a higher harmonic generation (HHG) radiation source for generating () EUV radiation. Operation of the HHG source is monitored using a wavefront sensor () which comprises an aperture array () and an image sensor (). A grating () disperses the radiation passing through each aperture so that the image detector captures positions and intensities of higher diffraction orders for different spectral components and different locations across the beam. In this way, the wavefront sensor can be arranged to measure a wavefront tilt for multiple harmonics at each location in said array. In one embodiment, the apertures are divided into two subsets (A) and (B), the gratings () of each subset having a different direction of dispersion. The spectrally resolved wavefront information () is used in feedback control () to stabilize operation of the HGG source, and/or to improve accuracy of metrology results. 169.-. (canceled)70. A radiation source arrangement operable to generate a beam of radiation , the radiation source arrangement comprising:a wavefront sensor configured to at least intermittently measure a tilt of a wavefront at an array of locations across a generated beam of radiation; anda processor configured to determine an operating condition of the radiation source arrangement based at least partly on the measured wavefront tilt,wherein the wavefront sensor is provided with a dispersive element at each location in the array, and the wavefront sensor is arranged to measure wavefront tilts with spectral resolution at each location in the array.71. The radiation source arrangement of claim 70 , wherein:the array of locations is defined by one or more spacing vectors;a direction of dispersion of each dispersive element is not parallel with any of the spacing vectors; andthe array of locations is divided into two or more subsets, the dispersive elements of each subset having a different direction of dispersion.72. The radiation source arrangement ...

Metrology apparatus, method of measuring a structure and lithographic apparatus

Disclosed is a metrology apparatus and method for measuring a structure formed on a substrate by a lithographic process. The metrology apparatus comprises an illumination system operable to provide measurement radiation comprising a plurality of wavelengths; and a hyperspectral imager operable to obtain a hyperspectral representation of a measurement scene comprising the structure, or a part thereof, from scattered measurement radiation subsequent to the measurement radiation being scattered by the structure.

Metrology in lithographic processes

An apparatus and method for estimating a parameter of a lithographic process and an apparatus and method for determining a relationship between a measure of quality of an estimate of a parameter of a lithographic process are provided. In the apparatus for estimating the parameter a processor is configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features.

Metrology in lithographic processes

An apparatus and method for estimating a parameter of a lithographic process and an apparatus and method for determining a relationship between a measure of quality of an estimate of a parameter of a lithographic process are provided. In the apparatus for estimating the parameter a processor is configured to determine a quality of the estimate of the parameter relating to the tested substrate based on a measure of feature asymmetry in the at least first features of the tested substrate and further based on a relationship determined for a plurality of corresponding at least first features of at least one further substrate representative of the tested substrate, the relationship being between a measure of quality of an estimate of the parameter relating to the at least one further substrate and a measure of feature asymmetry in the corresponding first features.

Illumination and detection apparatus for a metrology apparatus

Disclosed is an illumination and detection apparatus for a metrology tool, and associated method. The apparatus comprises an illumination arrangement operable to produce measurement illumination comprising a plurality of discrete wavelength bands and comprising a spectrum having no more than a single peak within each wavelength band. The detection arrangement comprises a detection beamsplitter to split scattered radiation into a plurality of channels, each channel corresponding to a different one of said wavelength bands; and at least one detector for separate detection of each channel.

Metrology method and associated metrology and lithographic apparatuses

Disclosed is a method to determine a performance indicator for a metrology process, comprising obtaining first measurement data relating to a first set of measurement conditions and determining a first measurement recipe based on said first measurement data. The at least one performance indicator is determined from one or more components of said first measurement data obtained from a component analysis or statistical decomposition. Alternatively, the at least one performance indicator is determined from a comparison of one or more first measurement values relating to said first measurement recipe and one or more second measurement values relating to a second measurement recipe, where second measurement recipe is different to said first measurement data and relates a second set of measurement conditions, said second set of measurement conditions being different to said first set of measurement conditions.

Mark position measuring apparatus and method, lithographic apparatus and device manufacturing method.

Inspection apparatus, inspection method and manufacturing method

Metrology targets are formed on a substrate (W) by a lithographic process. A target (T) comprising one or more grating structures is illuminated with spatially coherent radiation under different conditions. Radiation (650) diffracted by from said target area interferes with reference radiation (652) interferes with to form an interference pattern at an image detector (623). One or more images of said interference pattern are captured. From the captured image(s) and from knowledge of the reference radiation a complex field of the collected scattered radiation at the detector. A synthetic radiometric image (814) of radiation diffracted by each grating is calculated from the complex field. From the synthetic radiometric images (814, 814') of opposite portions of a diffractions spectrum of the grating, a measure of asymmetry in the grating is obtained. Using suitable targets, overlay and other performance parameters of the lithographic process can be calculated from the measured asymmetry.

Methods and patterning devices and apparatuses for measuring focus performance of a lithographic apparatus, device manufacturing method

A lithographic apparatus (LA) prints product features and at least one focus metrology pattern (T) on a substrate. The focus metrology pattern is defined by a reflective reticle and printing is performed using EUV radiation (404) incident at an oblique angle (Θ). The focus metrology pattern comprises a periodic array of groups of first features (422). A spacing (SI) between adjacent groups of first features is much greater than a dimension (CD) of the first features within each group. Due to the oblique illumination, the printed first features become distorted and/or displaced as a function of focus error. Second features 424 may be provided as a reference against which displacement of the first features may be seen. Measurement of this distortion and/or displacement may be by measuring asymmetry as a property of the printed pattern. Measurement can be done at longer wavelengths, for example in the range 350-800 nm.

Lithographic apparatus and method for performing a measurement

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). The lithographic apparatus has an inspection apparatus with an illumination system that utilizes illuminating radiation with a wavelength of 2-40 nm. The illumination system includes an optical element that splits the illuminating radiation into a first and a second illuminating radiation and induces a time delay to the first or the second illuminating radiation. A detector detects the radiation that has been scattered by a target structure. The inspection apparatus has a processing unit operable to control a time delay between the first scattered radiation and the second scattered radiation so as to optimize a property of the combined first and second scattered radiation.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an illumination source for generating measurement radiation for an inspection apparatus. The source generates at least first measurement radiation and second measurement radiation such that the first measurement radiation and the second measurement radiation interfere to form combined measurement radiation modulated with a beat component. The illumination source may be a HHG source. Also disclosed is an inspection apparatus comprising such a source and an associated inspection method.

Illumination source for an inspection apparatus, inspection apparatus and inspection method

Disclosed is an illumination source apparatus comprising a high harmonic generation medium (910), a pump radiation source and a spatial filter (940). The pump radiation source emits a beam (900) of pump radiation having a profile comprising no pump radiation in a central region of the beam and excites the high harmonic generation medium so as to generate high harmonic radiation (920). The pump radiation (950) and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation. The spatial filter is located beyond a focal plane of the beam of pump radiation, and blocks the pump radiation. Also disclosed is a method of generating high harmonic measurement radiation optimized for filtration of pump radiation therefrom.

Inspection apparatus and method of inspecting structures

Target structures such as overlay gratings (Ta and Tb) are formed on a substrate (W) by a lithographic process. The first target is illuminated with a spot of first radiation (456a, Sa) and simultaneously the second target is illuminated with a spot of second radiation (456b, Sb). A sensor (418) detects at different locations, portions (460x-, 460x+) of said first radiation that have been diffracted in a first direction by features of the first target and portions (460y-, 460y+) of said second radiation that have been diffracted in a second direction by features of the second target. Asymmetry in X and Y directions can be detected simultaneously, reducing the time required for overlay measurements in X and Y. The two spots of radiation at soft x-ray wavelength can be generated simply by exciting two locations (710a, 710b) in a higher harmonic generation (HHG) radiation source or inverse Compton scattering source.

Methods of aligning a diffractive optical system and diffractive optical element

A method of aligning a diffractive optical system, to be operated with an operating beam, comprises: aligning the diffractive optical system using an alignment beam having a different wavelength range from the operating beam and using a diffractive optical element (604 - 616) optimized to diffract the alignment beam and the operating beam in the same, or a predetermined, direction. In an example, the alignment beam comprises infra-red (IR) radiation and the operating beam comprises soft X-ray (SXR) radiation. The diffractive optical element is optimized by providing it with a first periodic structure with a first pitch (p IR ) and a second periodic structure with a second pitch (p SXR ). After alignment, the vacuum system is pumped down and in operation the SXR operating beam is generated by a high harmonic generation (HHG) optical source pumped by the IR alignment beam' optical source.

Apparatus for delivering gas and illumination source for generating high harmonic radiation

Disclosed is gas delivery system which is suitable for a high harmonic generation (HHG) radiation source which may be used to generate measurement radiation for an inspection apparatus. In such a radiation source, a gas delivery element delivers gas in a first direction. The gas delivery element has an optical input and an optical input, defining an optical path running in a second direction. The first direction is arranged relative to the second direction at an angle that is not perpendicular or parallel. Also disclosed is a gas delivery element having a gas jet shaping device, or a pair of gas delivery elements, one of which delivers a second gas, such that the gas jet shaping device or second gas is operable to modify a flow profile of the gas such that the number density of the gas falls sharply.

Apparatus for delivering gas

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. To ensure consistent quality of the patterns, metrology is used for process control and verification. In order to resolve smaller structures, the frequency of the radiation used in metrology is increased. One such method of generating suitably high frequency radiation is by using a high harmonic generation (HHG) radiation source. In such a radiation source, a gas delivery element (702) delivers gas (704) in a first direction (703). The gas delivery element has an optical input (706) and an optical output (708), defining an optical path (710) running in a second direction. The first direction is arranged relative to the second direction at an angle (724) that is not perpendicular or parallel.

Metrology parameter determination and metrology recipe selection

A method including: for a metrology target, having a first biased target structure and a second differently biased target structure, created using a patterning process, obtaining metrology data including signal data for the first target structure versus signal data for the second target structure, the metrology data being obtained for a plurality of different metrology recipes and each metrology recipe specifying a different parameter of measurement; determining a statistic, fitted curve or fitted function through the metrology data for the plurality of different metrology recipes as a reference; and identifying at least two different metrology recipes that have a variation of the collective metrology data of the at least two different metrology recipes from a parameter of the reference that crosses or meets a certain threshold.

Method to determine a patterning process parameter

A method to determine a patterning process parameter, the method comprising: for a target, calculating a first value for an intermediate parameter from data obtained by illuminating the target with radiation comprising a central wavelength; for the target, calculating a second value for the intermediate parameter from data obtained by illuminating the target with radiation comprising two different central wavelengths; and calculating a combined measurement for the patterning process parameter based on the first and second values for the intermediate parameter.

Metrology sensor for position metrology

Disclosed is a metrology device ( 1600 ) configured to produce measurement illumination comprising a plurality of illumination beams, each of said illumination beams being spatially incoherent or pseudo-spatially incoherent and comprising multiple pupil points in an illumination pupil of the metrology device. Each pupil point in each one of said plurality of illumination beams has a corresponding pupil point in at least one of the other illumination beams of said plurality of illumination beams thereby defining multiple sets of corresponding pupil points, and the pupil points of each set of corresponding pupil points are spatially coherent with respect to each other.

Method for inferring a local uniformity metric and associated appratuses

Disclosed is a method of inferring a value for at least one local uniformity metric relating to product structure and associated apparatus. The method comprises obtaining intensity data relating to a measurement of a target and describing at least one intensity distribution per target position of the target and determining at least one intensity indicator from said at least one intensity distribution. The value for the at least one local uniformity metric is inferred from the at least one intensity indicator.

Generating an alignment signal based on local alignment mark distortions

A method for generating an alignment signal is described. The method comprises detecting local dimensional distortions of an alignment mark and generating the alignment signal based on the alignment mark. The alignment signal is weighted based on the local dimensional distortions of the alignment mark. Detecting the local dimensional distortions comprises: irradiating the alignment mark with radiation, the alignment mark comprising a geometric feature; and detecting one or more phase and/or amplitude shifts in reflected radiation from the geometric feature. The one or more phase and/or amplitude shifts correspond to the local dimensional distortions of the geometric feature. A parameter of the radiation, an alignment inspection location within the geometric feature, an alignment inspection location on a layer of a structure, and/or a radiation beam trajectory across the geometric feature may be determined based on the one or more detected phase and/or amplitude shifts.

Method of metrology and associated apparatuses

Disclosed is a method of metrology. The method comprises measuring at least one surrounding observable parameter relating to a surrounding signal contribution to a metrology signal which comprises a contribution to said metrology signal which is not attributable to at least one target being measured and determining a correction from said surrounding signal observable parameter. The correction is used to correct first measurement data relating to measurement of one or more targets using measurement radiation forming a measurement spot on one or more of said one or more targets which is larger than one of said targets.

Metrology method for measuring an etched trench and associated metrology apparatus

A method of determining at least one homogeneity metric describing homogeneity of an etched trench on a substrate formed by a lithographic manufacturing process. The method comprises obtaining one or more images of the etched trench, wherein each of said one or more images comprises a spatial representation of one or more parameters of scattered radiation as detected by a detector or camera (365) following scattering and/or diffraction from the etched trench; and measuring homogeneity along the length of the etched trench on said one or more images to determine said at least one homogeneity metric.

Illumination and detection apparatus for a metrology apparatus

Disclosed is an illumination and detection apparatus for a metrology tool, and associated method. The apparatus comprises an illumination arrangement operable to produce measurement illumination comprising a plurality of discrete wavelength bands and comprising a spectrum having no more than a single peak within each wavelength band. The detection arrangement comprises a detection beamsplitter to split scattered radiation into a plurality of channels, each channel corresponding to a different one of said wavelength bands; and at least one detector for separate detection of each channel.

Position measuring apparatus, position measuring method, lithographic apparatus and device manufacturing method

An apparatus for measuring positions of marks on a substrate, includes an illumination arrangement for supplying radiation with a predetermined illumination profile across a pupil of the apparatus, an objective lens for forming a spot of radiation on a mark using radiation supplied by said illumination arrangement, a radiation processing element for processing radiation that is diffracted by the mark, a first detection arrangement for detecting variations in an intensity of radiation output by the radiation processing element and for calculating therefrom a position of the mark, an optical arrangement, a second detection arrangement, wherein the optical arrangement serves to direct diffracted radiation to the second detection arrangement, and wherein the second detection arrangement is configured to detect size and/or position variations in the radiation and to calculate therefrom a defocus and/or local tilt of the mark.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes an alignment sensor including a self-referencing interferometer for reading the position of an alignment target comprising a periodic structure. An illumination optical system for focusing radiation into a spot on said structure. An asymmetry detection optical system receives a share of positive and negative orders of radiation diffracted by the periodic structure, and forms first and second images of said spot on first and second detectors respectively, wherein said negative order radiation is used to form the first image and said positive order radiation is used to form the second image. A processor for processing together signals from said first and second detectors representing intensities of said positive and negative orders to produce a measurement of asymmetry in the periodic structure. The asymmetry measurement can be used to improve accuracy of the position read by the alignment sensor.

Position measuring apparatus, position measuring method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an objective lens to direct radiation on a mark using radiation supplied by an illumination arrangement; an optical arrangement to receive radiation diffracted and specularly reflected by the mark, wherein the optical arrangement is configured to provide a first image and a second image, the first image being formed by coherently adding specularly reflected radiation and positive diffraction order radiation and the second image being formed by coherently adding specularly reflected radiation and negative diffraction order radiation; and a detection arrangement to detect variation in an intensity of radiation of the first and second images and to calculate a position of the mark in a direction of measurement therefrom.

Mark position measuring apparatus and method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an illumination arrangement to direct radiation across a pupil of the apparatus, the illumination arrangement comprising an illumination source to provide multiple-wavelength radiation of substantially equal polarization and a wave plate to alter the polarization of the radiation in dependency of the wavelength, such that radiation of different polarization is supplied; an objective lens to direct radiation on the mark using the radiation supplied by the illumination arrangement while scanning the radiation across the mark in a scanning direction; a radiation processing element to process radiation that is diffracted by the mark and received by the objective lens; and a detection arrangement to detect variation in an intensity of radiation output by the radiation processing element during the scanning and to calculate from the detected variation a position of the mark in at least a first direction of measurement.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes a sensor, such as an alignment sensor including a self-referencing interferometer, configured to determine the position of an alignment target comprising a periodic structure. An illumination optical system focuses radiation of different colors and polarizations into a spot which scans the structure. Multiple position-dependent signals are detected and processed to obtain multiple candidate position measurements. Asymmetry of the structure is calculated by comparing the multiple position- dependent signals. The asymmetry measurement is used to improve accuracy of the position read by the sensor. Additional information on asymmetry may be obtained by an asymmetry sensor receiving a share of positive and negative orders of radiation diffracted by the periodic structure to produce a measurement of asymmetry in the periodic structure.

Polarization independent interferometer

Apparatus, systems, and methods are used for detecting the alignment of a feature on a substrate using a polarization independent interferometer. The apparatus, system, and methods include optical elements that receive light that has diffracted or scattered from a mark on a substrate. The optical elements may split the diffracted light into multiple subbeams of light which are detected by one or more detectors. The diffracted light may be combined optically or during processing after detection. The system may determine alignment and/or overlay based on the received diffracted light having any polarization angle or state.

Mark position determination method

A method of determining positions of marks on a substrate, the marks comprising structures arranged periodically in at least a first direction, at least some of the structures comprising periodic sub-structures, the sub-structures having a smaller period than the structures, the marks being formed with positional offsets between the sub-structures and the structures, the positional offsets being caused by a combination of both known and unknown components, the method comprising illuminating a plurality of the marks with radiation beams having different characteristics and detecting radiation diffracted by the marks using one or more detectors which produce output signals processing the signals, wherein the processing comprises discriminating between constituent parts of the signals, the discriminating being based on a variation of the signals as a function of spatial positions of the marks on the substrate, selecting at least one of the constituent parts of the signals, and using the at least one selected constituent part of the signals, and information relating to differences between the known components, to calculate a corrected position of at least one mark.

Position sensor, lithographic apparatus and method for manufacturing devices

An alignment sensor in a lithographic apparatus comprises an optical system (500; 600) configured to deliver, collect and process radiation selectively in a first waveband (e.g. 500-900 nm) and/or in a second waveband (e.g. 1500-2500 nm). The radiation of the first and second wavebands share a common optical path (506-508; 606) in at least some portion of the optical system, while the radiation of the first waveband is processed by a first processing sub-system (552a) and the radiation of the second waveband (552b) is processed by a second processing sub-system. The processing subsystems in one example comprise self-referencing interferometers (556a/556b; 656a/656b). The radiation of the second waveband allow marks to be measure through an opaque layer (308) such as carbon hard mask. Optical coatings and other components of each processing sub-system can be tailored to the respective waveband, without completely duplicating the optical system.

Metrology sensor, lithographic apparatus and method for manufacturing devices

Disclosed is a metrology sensor apparatus and associated method. The metrology sensor apparatus comprises an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state and an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark. The metrology mark comprises a main structure and changes, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to the polarization state of the second portion of the scattered radiation. The metrology sensor apparatus further comprises an optical filtering system which filters out the second portion of the scattered radiation based on its polarization state.

Metrology sensor for position metrology

Disclosed is a metrology device (1600) configured to produce measurement illumination comprising a plurality of illumination beams, each of said illumination beams being spatially incoherent or pseudo-spatially incoherent and comprising multiple pupil points in an illumination pupil of the metrology device. Each pupil point in each one of said plurality of illumination beams has a corresponding pupil point in at least one of the other illumination beams of said plurality of illumination beams thereby defining multiple sets of corresponding pupil points, and the pupil points of each set of corresponding pupil points are spatially coherent with respect to each other.

Metrology method and associated metrology and lithographic apparatuses

Disclosed is a metrology method relating to measurement of a structure on a substrate, said structure being subject to one or more asymmetric deviation. The method comprises obtaining at least one intensity asymmetry value relating to the asymmetric deviation, wherein the at least one intensity asymmetry value comprises a metric related to a difference or imbalance between the respective intensities or amplitudes of at least two diffraction orders of radiation diffracted by said structure; determining at least one phase offset value corresponding to the one or more asymmetric deviation based on said at least one intensity asymmetry value; and determining one or more measurement correction for said one or more asymmetric deviation from the one or more phase offset.

Position measuring apparatus, position measuring method, lithographic apparatus and device manufacturing method

An apparatus for measuring positions of marks on a substrate, includes an illumination arrangement for supplying radiation with a predetermined illumination profile across a pupil of the apparatus, an objective lens for forming a spot of radiation on a mark using radiation supplied by said illumination arrangement, a radiation processing element for processing radiation that is diffracted by the mark, a first detection arrangement for detecting variations in an intensity of radiation output by the radiation processing element and for calculating therefrom a position of the mark, an optical arrangement, a second detection arrangement, wherein the optical arrangement serves to direct diffracted radiation to the second detection arrangement, and wherein the second detection arrangement is configured to detect size and/or position variations in the radiation and to calculate therefrom a defocus and/or local tilt of the mark.

Method and apparatus for measuring asymmetry of a microstructure, position measuring method, position measuring apparatus, lithographic apparatus and device manufacturing method

A lithographic apparatus includes an alignment sensor including a self-referencing interferometer for reading the position of an alignment target comprising a periodic structure. An illumination optical system for focusing radiation into a spot on said structure. An asymmetry detection optical system receives a share of positive and negative orders of radiation diffracted by the periodic structure, and forms first and second images of said spot on first and second detectors respectively, wherein said negative order radiation is used to form the first image and said positive order radiation is used to form the second image. A processor for processing together signals from said first and second detectors representing intensities of said positive and negative orders to produce a measurement of asymmetry in the periodic structure. The asymmetry measurement can be used to improve accuracy of the position read by the alignment sensor.

Position measuring apparatus, position measuring method, lithographic apparatus and device manufacturing method

An apparatus to measure the position of a mark, the apparatus including an objective lens to direct radiation on a mark using radiation supplied by an illumination arrangement; an optical arrangement to receive radiation diffracted and specularly reflected by the mark, wherein the optical arrangement is configured to provide a first image and a second image, the first image being formed by coherently adding specularly reflected radiation and positive diffraction order radiation and the second image being formed by coherently adding specularly reflected radiation and negative diffraction order radiation; and a detection arrangement to detect variation in an intensity of radiation of the first and second images and to calculate a position of the mark in a direction of measurement therefrom.

Position sensor, lithographic apparatus and method for manufacturing devices

An alignment sensor for a lithographic apparatus has an optical system configured to deliver, collect and process radiation selectively in a first waveband (e.g. 500-900 nm) and/or in a second waveband (e.g. 1500-2500 nm). The radiation of the first and second wavebands share a common optical path in at least some portion of the optical system, while the radiation of the first waveband is processed by a first processing sub-system and the radiation of the second waveband is processed by a second processing sub-system. The processing subsystems in one example include self-referencing interferometers. The radiation of the second waveband allows marks to be measured through an opaque layer. Optical coatings and other components of each processing sub-system can be tailored to the respective waveband, without completely duplicating the optical system.