Fluorine control system with fluorine monitor

An excimer laser system with a real time fluorine monitor and an automatic fluorine control system to permit precise control of the fluorine concentration within the laser chamber. Cleaned laser gas is extracted from the laser chamber and directed through an F 2 sample cell prior to returning to the chamber through one of the chamber window housings. A UV light beam is directed through the F 2 sample cell and the amount of absorption of the light is measured. In preferred embodiments the absorption is measured by detecting with a photo detector the amount of light which passes through the cell. The photo detector provides a feedback signal which is used by a laser controller to automatically control fluorine concentration in the chamber to within desired ranges. In another preferred embodiment an acoustic detector detects acoustic signals resulting from absorbed light pulses. This invention provides a substantially real time measurement of fluorine concentration.

Reliable, modular, production quality narrow-band high rep rate ArF excimer laser

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz with a full width half, maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber, a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.

EUV collector debris management

A method and apparatus that may comprise an EUV light producing mechanism utilizing an EUV plasma source material comprising a material that will form an etching compound, which plasma source material produces EUV light in a band around a selected center wavelength comprising: an EUV plasma generation chamber; an EUV light collector contained within the chamber having a reflective surface containing at least one layer comprising a material that does not form an etching compound and/or forms a compound layer that does not significantly reduce the reflectivity of the reflective surface in the band; an etchant source gas contained within the chamber comprising an etchant source material with which the plasma source material forms an etching compound, which etching compound has a vapor pressure that will allow etching of the etching compound from the reflective surface. The etchant source material may comprises a halogen or halogen compound. The etchant source material may be selected based ...

High power gas discharge laser with helium purged line narrowing unit

A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the uses of helium purge as compared to prior art nitrogen purges.In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Laser system

An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the second seed laser.

REGENERATIVE RING RESONATOR

A laser includes a regenerative ring resonator that includes a discharge chamber having electrodes and a gain medium between the electrodes for producing a laser beam; a partially-reflective optical coupler, and a beam modification optical system in the path of the laser beam. The beam modification optical system transversely expands a profile of the laser beam such that the near field laser beam profile uniformly fills each aperture within the laser and such that the regenerative ring resonator remains either conditionally stable or marginally unstable when operating the laser at powers that induce thermal lenses in optical elements inside the regenerative ring resonator.

Wavemeter for gas discharge laser

An optical configuration to illuminate an etalon in a laser wavemeter with a minimum level of light intensity. The system includes optical components to direct a portion of the laser output beam representing the entire cross section of the beam, through an etalon positioned in an etalon housing and onto a photodetector. A first lens condenses the size of the beam sample, and a second lens re-collimates the beam which then passes into the etalon housing, ensuring that all of the spatial components of the beam are adequately sampled. A diffractive diffusing element is incorporated into the optical path. In a preferred embodiment, the diffractive diffusing element is placed within the etalon housing between said plano-concave lens and the etalon. In another preferred embodiment, the diffusing element is located up stream but outside the housing in the optical path.

Immersion lithography laser light source with pulse stretcher

An apparatus and method which may comprise a pulsed gas discharge laser which may comprise a seed laser portion; an amplifier portion receiving the seed laser output and amplifying the optical intensity of each seed pulse; a pulse stretcher which may comprise: a first beam splitter operatively connected with the first delay path and a second pulse stretcher operatively connected with the second delay path; a first optical delay path tower containing the first beam splitter; a second optical delay path tower containing the second beam splitter; one of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors located in the first tower and in the second tower; the other of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors only in one of the first tower and the second tower.

Master Oscillator-Power Amplifier Drive Laser With Pre-Pulse for EUV Light Source

A device is described herein which may comprise an optical amplifier having a gain band including wavelengths λand λ, with λ≠λ; a pre-pulse seed laser having a tuning module for tuning a pre-pulse output to wavelength λ; a main pulse seed laser generating a laser output having wavelength, λ; and a beam combiner for directing the pre-pulse output and the main pulse output on a common path through the optical amplifier. 1{'sub': 1', '2', '1', '2, 'an optical amplifier having a gain band including wavelengths λand λ, with λ≠λ;'}{'sub': '1', 'a pre-pulse seed laser having a tuning module for tuning a pre-pulse output to wavelength λ;'}{'sub': 2', '2, 'a main pulse seed laser generating a laser output having wavelength, λ, wherein at least one of said pre-pulse seed laser and said main pulse seed laser has a gain medium comprising CO; and'}a beam combiner for directing the pre-pulse output and the main pulse output on a common path through the optical amplifier.. A device comprising: The present application is a continuation of U.S. patent application Ser. No. 13/077,236, filed on Mar. 31, 2011, and published on Dec. 29, 2011 as US-2011-0317256-A1, entitled MASTER OSCILLATOR-POWER AMPLIFIER DRIVE LASER WITH PRE-PULSE FOR EUV LIGHT SOURCE, Attorney Docket No. 2009-0038-02, which claims the benefit of U.S. Provisional Application No. 61/398,452, filed on Jun. 24, 2010, entitled MASTER OSCILLATOR-POWER AMPLIFIER DRIVE LASER WITH PRE-PULSE FOR EUV LIGHT SOURCE, Attorney Docket No. 2009-0038-01, the entire contents of all of which are hereby incorporated by reference herein.The present application is related to U.S. patent application Ser. No. 12/004,905, filed on Dec. 20, 2007, entitled DRIVE LASER FOR EUV LIGHT SOURCE, Attorney Docket Number 2006-0065-01; U.S. patent application Ser. No. 11/786,145 filed on Apr. 10, 2007, entitled LASER PRODUCED PLASMA EUV LIGHT SOURCE, Attorney Docket Number 2007-0010-02; U.S. patent application Ser. No. 11/827,803 filed on Jul. 13, 2007, ...

Laser output beam wavefront splitter for bandwidth spectrum control

Apparatus/method providing bandwidth control in narrow band short pulse duration gas discharge laser output light pulse beam producing systems, producing a beam comprising pulses at selected pulse repetition races, e.g., comprising a dispersive bandwidth selection optic selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the beam containing the respective pulse on the optic; a tuning mechanism operative to select at least one angle of incidence of the beam containing the respective pulse upon the optic; the tuning mechanism comprising a plurality of incidence angle selection elements each defining an angle of incidence for a different spatially separated but not temporally separated portion of the pulse to return from the optic a laser light pulse comprising a plurality of spatially separated but not temporally separated portions, each having one of at least two different selected center wavelengths.

High repetition rate laser produced plasma EUV light source

An EUV light source apparatus and method are disclosed, which may comprise a pulsed laser providing laser pulses at a selected pulse repetition rate focused at a desired target ignition site; a target formation system providing discrete targets at a selected interval coordinated with the laser pulse repetition rate; a target steering system intermediate the target formation system and the desired target ignition site; and a target tracking system providing information about the movement of target between the target formation system and the target steering system, enabling the target steering system to direct the target to the desired target ignition site. The apparatus and method may comprise a vessel having and intermediate wall with a low pressure trap allowing passage of EUV light and maintaining a differential pressure across the low pressure trap.

High speed magnetic modulator voltage and temperature timing compensation circuit

An improvement over prior art voltage timing compensation circuits is achieved by incorporating a function generator to provide a more accurate non-linear compensation to pulse timing delay, which is typically a non-linear function of voltage. An improvement over prior art temperature timing compensation circuits is achieved by providing for actual temperature measurements to be made and used to drive the timing compensation circuitry for a more accurate temperature timing compensation than provided by prior art temperature synthesis, while still using a relatively simple compensating circuit. In some embodiments a timing compensation circuit combines both voltage and temperature timing compensation.

Laser system

An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the second seed laser.

Laser system

An apparatus/method which may comprise: a very high power line narrowed lithography laser light source which may comprise: a solid state seed laser system which may comprise: a pre-seed laser providing a pre-seed laser output; a fiber amplifier receiving the pre-seed laser output and providing an amplified seed laser pulse which may comprise: a pulse having a nominal wavelength outside of the DUV range; a frequency converter converting to essentially the wavelength of the amplifier gain medium; a first and a second gas discharge laser amplifier gain medium operating at different repetition rates from that of the seed laser output; a beam divider providing the amplifier gain mediums with output pulses from the seed laser; a beam combiner combining the outputs of each respective amplifier gain medium to provide a laser output light pulse beam having the pulse repetition rate of the solid state seed laser system.

EUV LIGHT SOURCE WITH SUBSYSTEM(S) FOR MAINTAINING LPP DRIVE LASER OUTPUT DURING EUV NON-OUTPUT PERIODS

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet. 1. An Extreme Ultraviolet (EUV) light source producing EUV pulses in at least two burst periods , the at least two burst periods separated by an intervening period , the EUV light source comprising:a droplet generator producing droplets of target material during each of the at least two burst periods and during the intervening period;a laser source producing laser pulses during the each of the at least two burst periods and during the intervening period; anda system operable to reconfigure the EUV light source from a first configuration in which the laser pulses generated during the each of the at least two burst periods interact with the droplets of target material to produce a plasma having first characteristics and a second configuration in which laser pulses generated during the intervening period do not produce the plasma having the first characteristics.2. The EUV light source of wherein the laser pulses generated during the intervening period produces plasma having second characteristics different from the first characteristics.3. The EUV light source of wherein the laser pulses generated during the intervening period do not produce plasma.4. The EUV light source of wherein the target material is subject to a first disturbance during the each of the at ...

SYSTEM, METHOD AND APPARATUS FOR DROPLET CATCHER FOR PREVENTION OF BACKSPLASH IN A EUV GENERATION CHAMBER

A system and method generating an extreme ultraviolet light in an extreme ultraviolet light chamber including a collector mirror, a droplet generation system having a droplet outlet aligned to output a plurality of droplets along a target material path and a first catch including a first open end substantially aligned to the target material path and at least one internal surface oriented toward a second end of the first catch, the second end being opposite from the first open end.

Laser discharge chamber passivation by plasma

Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than ...

Systems and methods for implementing an interaction between a laser shaped as line beam and a film deposited on a substrate

A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.

Adaptive laser system for an extreme ultraviolet light source

A system for an extreme ultraviolet (EUV) light source includes an optical amplifier including a gain medium positioned on a beam path, the optical amplifier configured to receive a light beam at an input and to emit an output light beam for an EUV light source at an output; a feedback system that measures a property of the output light beam and produces a feedback signal based on the measured property; and an adaptive optic positioned in the beam path and configured to receive the feedback signal and to adjust a property of the output light beam in response to the feedback signal.

Bandwidth control technique for a laser

A technique for bandwidth control of an electric discharge laser. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection means and a bandwidth control having a time response of less than about 1.0 millisecond. In a preferred embodiment wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second within a very narrow range of pivot angles to cause a dither in nominal wavelength values to produce a desired effective bandwidth of series of laser pulses.

DUV light source optical element improvements

A high power narrow band, high repetition rate laser light source optical improvement apparatus and methods are disclosed with a fast angularly positionable mirror having a mirror mounting frame, a reflective optic with a coefficient different from that of the mounting frame, at least one flexure mount fromed in the mounting frame that is flexible having flexure arm attached the flexture to the mounting frame. The apparatus may include a flexure force mechanism having an elongated rod. The force mechanism may pre-stress the flexure. The mirror maybe a grating which includes a substrate with metallic layer formed on the substrate, and a protective coating made of silica formed on the reflective metallic layer. The grating maybe actively tuned using an electro- or magneto-sensitive element. Oxides of the metal in the reflective layer may be removed by a hydrogen purge system exposed to deep ultraviolet radiation.

Laser system

A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

High power excimer laser with a pulse stretcher

An apparatus and method is disclosed which may comprise a high power excimer or molecular fluorine gas discharge laser DUV light source system which may comprise: a pulse stretcher which may comprise: an optical delay path mirror, an optical delay path mirror gas purging assembly which may comprise: a purging gas supply system directing purging gas across a face of the optical delay line mirror. The optical delay path mirror may comprise a plurality of optical delay path mirrors; the purging gas supply system may direct purging gas across a face of each of the plurality of optical delay line mirrors. The purging gas supply system may comprise: a purging gas supply line; a purging gas distributing and directing mechanism which may direct purging gas across the face of the respective optical delay path mirror.

Gas discharge laser line narrowing module

A line narrowed gas discharge laser system and method of operating same is disclosed which may comprise a dispersive center wavelength selective element; a beam expander comprising a plurality of refractive elements; a refractive element positioning mechanism positioning at least one of the refractive elements to modify an angle of incidence of a laser light beam on the dispersive center wavelength selection element; each of the dispersive center wavelength selection element and the beam expander being aligned with each other and with a housing containing at least the dispersive center wavelength selection element; a housing positioning mechanism positioning the housing with respect to an optical axis of the gas discharge laser system. The dispersive element may comprise a grating and the beam expander may comprise a plurality of prisms. The housing may contain the dispersive center wavelength selective element and the beam expander. The housing positioning element may comprise a position ...

System and Method for Seed Laser Mode Stabilization

A method and apparatus for stabilizing the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed. In one embodiment, the cavity length of the laser may be adjusted by means of a movable mirror forming one end of the cavity. The time delay from the release of an output pulse to the lasing threshold next being reached is measured at different mirror positions, and a mirror position selected which results in a cavity mode being aligned with the gain peak of the laser, thus producing a minimum time delay from an output pulse of the laser to the next lasing threshold. A Q-switch in the laser allows for pre-lasing and thus jitter-free timing of output pulses. Feedback loops keep the laser output at maximum gain and efficiency, and the attenuation and timing at a desired operating point. 1. A system for producing output laser pulses , comprising:a laser having an optical cavity including a movable optical component, such that moving the optical component changes the length of the optical cavity, and lasing when power in the optical cavity reaches a lasing threshold;an actuator for positioning the optical component within a predetermined range;a variable attenuator in the optical cavity for limiting the rate at which power in the laser increases and thus controlling the time at which the lasing threshold is reached and the time at which the output pulse is released;a sensor for measuring the output power of the laser at a given moment;a computing device for calculating the time delay from the release of an output pulse to the time the lasing threshold is again reached; anda first feedback loop having a first controller for causing the actuator to position the optical component so that the time delay from the release of an output pulse to the time the lasing threshold is again reached is at a minimum.2. The system of further comprising a second feedback loop having a second controller for causing an adjustment in the variable ...

EUV light source with subsystem(s) for maintaining LPP drive laser output during EUV non-output periods

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet.

Method and apparatus for EUV plasma source target delivery

An EUV plasma formation target delivery system and method is disclosed which may comprise: a target droplet formation mechanism comprising a magneto-restrictive or electro-restrictive material, a liquid plasma source material passageway terminating in an output orifice; a charging mechanism applying charge to a droplet forming jet stream or to individual droplets exiting the passageway along a selected path; a droplet deflector intermediate the output orifice and a plasma initiation site periodically deflecting droplets from the selected path, a liquid target material delivery mechanism comprising a liquid target material delivery passage having an input opening and an output orifice; an electromotive disturbing force generating mechanism generating a disturbing force within the liquid target material, a liquid target delivery droplet formation mechanism having an output orifice; and/or a wetting barrier around the periphery of the output orifice.

Method and System for Managing Light Source Operation

A laser light source experiencing an EOL condition, which might otherwise cause an unscheduled shutdown, is instead operated in a diminished capacity in one or more predetermined or calculated increments. Operating in such diminished capacity continues until the laser system can undergo appropriate maintenance either during a regularly scheduled shutdown or a newly scheduled shutdown. In the meantime, the diminished capacity of the laser system is accommodated by the utilization tool, as appropriate.

Systems and methods to shape laser light as a homogeneous line beam for interaction with a film deposited on a substrate

Systems and methods are disclosed for shaping and homogenizing a laser beam for interaction with a film. The shaping and homogenizing system may include a lens array and a lens that is positioned to receive laser light from the lens array and produce a respective elongated image in a plane for each lens in the lens array. In addition, the system may include a beam stop having an edge that is positioned in the plane, and a moveable mount rotating a lens of the lens array to vary an alignment between one of the elongated images and the beam stop edge.

Gas discharge ultraviolet wavemeter with enhanced illumination

The present invention provides a wavemeter for an ultraviolet laser capable of long life beam quality monitoring in a pulsed ultraviolet laser system at pulse rates greater than 2000 Hz at pulse energies at 5 mJ or greater. In a preferred embodiment an enhanced illumination configuration reduces per pulse illumination of an etalon by a factor of 28 compared to a popular prior art configuration. Optics are provided in this embodiment which reduce light entering the etalon to only that amount needed to illuminate a linear photo diode array positioned to measure interference patterns produced by the etalon. In this preferred embodiment two sample beams produced by reflections from two surfaces of a beam splitter are diffused by a defractive diffuser and the output of the defractive diffuser is focused on two separate secondary diffusers effectively combining both beams in two separate spectrally equivalent diffuse beams. One beam is used for wavelength and bandwidth measurement and the other ...

Regenerative ring resonator

A laser includes a regenerative ring resonator that includes a discharge chamber having electrodes and a gain medium between the electrodes for producing a laser beam; a partially-reflective optical coupler, and a beam modification optical system in the path of the laser beam. The beam modification optical system transversely expands a profile of the laser beam such that the near field laser beam profile uniformly fills each aperture within the laser and such that the regenerative ring resonator remains either conditionally stable or marginally unstable when operating the laser at powers that induce thermal lenses in optical elements inside the regenerative ring resonator.

Line selected F2 two chamber laser system

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in a F₂ laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds ...

Very narrow band, two chamber, high rep-rate gas discharge laser system

An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected ...

Laser system

A method and apparatus may comprise a laser light source system which may comprise a solid state laser seed beam source providing a seed laser output; a frequency conversion stage converting the seed laser output to a wavelength suitable for seeding an excimer or molecular fluorine gas discharge laser; an excimer or molecular fluorine gas discharge laser gain medium amplifying the converted seed laser output to produce a gas discharge laser output at approximately the converted wavelength. The excimer or molecular fluorine laser may be selected from a group comprising XeCl, XeF, KrF, ArF and F2 laser systems. The laser gain medium may comprise a power amplifier. The power amplifier may comprise a single pass amplifier stage, a multiple-pass amplifier stage, a ring power amplification stage or a power oscillator. The ring power amplification stage may comprise a bow-tie configuration or a race track configuration.

Two chamber F2 laser system with F2 pressure based line selection

The present invention provides an injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The parameters chamber can be controlled separately permitting optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment is a F2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In this preferred embodiment, both of the chambers and the laser optics are mounted on a vertical optical table within a laser enclosure. In the preferred MOPA embodiment, each ...

Laser produced plasma EUV light source

A device is disclosed herein which may include a plasma generating system comprising a source of target material droplets and a laser producing a beam irradiating the droplets at an irradiation region, the plasma producing EUV radiation, wherein the droplet source comprises a fluid exiting an orifice and a sub-system producing a disturbance in the fluid which generates droplets having differing initial velocities causing the spacing between at least some adjacent droplets to decrease as the droplets travel to the irradiation region.

Laser system

A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

ADAPTIVE LASER SYSTEM FOR AN EXTREME ULTRAVIOLET LIGHT SOURCE

A system for an extreme ultraviolet (EUV) light source includes an optical amplifier including a gain medium positioned on a beam path, the optical amplifier configured to receive a light beam at an input and to emit an output light beam for an EUV light source at an output; a feedback system that measures a property of the output light beam and produces a feedback signal based on the measured property; and an adaptive optic positioned in the beam path and configured to receive the feedback signal and to adjust a property of the output light beam in response to the feedback signal. 1. An extreme ultraviolet light source comprising: two or more optical amplifiers, each comprising a gain medium positioned on a beam path, and each optical amplifier configured to receive an input light beam that travels along the beam path at an input and to emit an output light beam at an output and onto the beam path;', 'one or more adaptive optical elements positioned on the beam path, the adaptive optical elements being adjustable in response to a feedback signal; and', 'a feedback system coupled to the one or more adaptive optical elements, the feedback system comprising a sensor positioned to receive radiation that propagates in the beam path and the feedback system configured to generate the feedback signal based on a property measured by the sensor;, 'a source that produces an amplified light beam, the source comprisinga vacuum chamber;a target material delivery system that directs target material toward a target location that is inside of the vacuum chamber and receives the amplified light beam, the target material comprising a material that emits extreme ultraviolet light when converted to plasma; anda collector inside the vacuum chamber, the collector positioned to receive and direct the emitted extreme ultraviolet light.2. The extreme ultraviolet light source of claim 1 , wherein the one or more adaptive optical elements comprise at least one adaptive optical element ...

Reliable, modular, production quality narrow-band high rep rate F2 laser

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved communication module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel ...

Four KHz gas discharge laser system

The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Extendable electrode for gas discharge laser

A movable electrode assembly for use in a laser system, includes a first electrode having a first discharge surface, a second electrode having a second discharge surface. The second electrode being arranged opposite from the first electrode. The second discharge surface being spaced apart from the first discharge surface by a discharge gap. A discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A method of adjusting a discharge gap is also disclosed.

Laser system

An apparatus/method which may comprise: a very high power line narrowed lithography laser light source which may comprise: a solid state seed laser system which may comprise: a pre-seed laser providing a pre-seed laser output; a fiber amplifier receiving the pre-seed laser output and providing an amplified seed laser pulse which may comprise: a pulse having a nominal wavelength outside of the DUV range; a frequency converter converting to essentially the wavelength of the amplifier gain medium; a first and a second gas discharge laser amplifier gain medium operating at different repetition rates from that of the seed laser output; a beam divider providing the amplifier gain mediums with output pulses from the seed laser; a beam combiner combining the outputs of each respective amplifier gain medium to provide a laser output light pulse beam having the pulse repetition rate of the solid state seed laser system.

High repetition rate laser produced plasma EUV light source

An EUV light source apparatus and method are disclosed, which may comprise a pulsed laser providing laser pulses at a selected pulse repetition rate focused at a desired target ignition site; a target formation system providing discrete targets at a selected interval coordinated with the laser pulse repetition rate; a target steering system intermediate the target formation system and the desired target ignition site; and a target tracking system providing information about the movement of target between the target formation system and the target steering system, enabling the target steering system to direct the target to the desired target ignition site. The target tracking system may provide information enabling the creation of a laser firing control signal, and may comprise a droplet detector comprising a collimated light source directed to intersect a point on a projected delivery path of the target, having a respective oppositely disposed light detector detecting the passage of the ...

Injection seeded F2 lithography laser

A tunable injection seeded very narrow band F2 lithography laser. The laser combines modular design features of prior art long life releasable lithography lasers with special F2 line narrowing and tuning techniques applied to a seed beam operated in a first gain medium which beam is used to stimulate narrow band lasing in a second gain medium to produce a very narrow band laser beam useful for integrated circuit lithography.

Electric discharge laser with active wavelength chirp correction

Electric discharge laser with active chirp correction. This application discloses techniques for moderating and dispensing these pressure waves. In some lasers small predictable patterns remain which can be substantially corrected with active wavelength control using relatively slow wavelength control instruments of the prior art. In a preferred embodiment a simple learning algorithm is described to allow advance tuning mirror adjustment in anticipation of the learned chirp pattern. Embodiments include stepper motors having very fine adjustments so that size of tuning steps are substantially reduced for more precise tuning. However, complete elimination of wavelength chirp is normally not feasible with structural changes in the laser chamber and advance tuning; therefore, Applicants have developed equipment and techniques for very fast active chirp correction. Improved techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver. In another preferred ...

Immersion lithography laser light source with pulse stretcher

An apparatus and method which may comprise a pulsed gas discharge laser which may comprise a seed laser portion; an amplifier portion receiving the seed laser output and amplifying the optical intensity of each seed pulse; a pulse stretcher which may comprise: a first beam splitter operatively connected with the first delay path and a second pulse stretcher operatively connected with the second delay path; a first optical delay path tower containing the first beam splitter; a second optical delay path tower containing the second beam splitter; one of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors located in the first tower and in the second tower; the other of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors only in one of the first tower and the second tower.

High power gas discharge laser with helium purged line narrowing unit

A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the use of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Oscillator-amplifier drive laser with seed protection for an EUV light source

As disclosed herein, in a first aspect, a device may comprise: an oscillator producing a light output on a beam path; a target material for interaction with light on the beam path at an irradiation site; a beam delay on the beam path the beam delay having a beam folding optical arrangement; and a switch positioned along the beam path and interposed between the oscillator and the beam delay; the switch closable to divert at least a portion of light on the beam path from the beam path, the switch having close time, t 1 and the beam path having a length, L 1 , along the path from the switch to the irradiation site; with t 1 <cL 1 , where c is the speed of light on the path, to protect the oscillator.

High resolution etalon-grating spectrometer

A high resolution etalon-grating spectrometer. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light passing through the slit is collimated and the collimated light illuminates a grating positioned in an approximately Littrow configuration which disburses the light according to wavelength. A portion of the dispursed light representing the wavelength corresponding to the selected etalon fringe is passed through a second slit and monitored by a light detector. When the etalon and the grating are tuned to the same precise wavelength a slit function is defined which is extremely narrow such as about ...

High resolution spectral measurement device

A high resolution spectral measurement device. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow-band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light passing through the slit is collimated and the collimated light illuminates a grating positioned in an approximately Littrow configuration which disburses the light according to wavelength. A portion of the dispursed light representing the wavelength corresponding to the selected etalon fringe is passed through a second slit and monitored by a light detector. When the etalon and the grating are tuned to the same precise wavelength a slit function is defined which is extremely narrow such as about ...

EXTENDABLE ELECTRODE FOR GAS DISCHARGE LASER

A movable electrode assembly for use in laser system includes a first electrode, a second electrode arranged opposite from the first electrode, the second electrode being spaced apart from the first electrode by a discharge gap and a discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A movable electrode assembly for integration into a housing of a laser system includes a first electrode having a discharge surface, a second electrode having a discharge surface, such that the discharge surface of the first electrode and the discharge surface of the second electrode face each other in a spaced apart setting that defines a desired discharge gap, and a mechanism for moveably adjusting the spaced apart setting toward the desired discharge gap. A method of adjusting a discharge gap is also disclosed.

Line narrowing module

An apparatus is disclosed which may comprise a grating receiving light, a first prism moveable to coarsely select an angle of incidence of the light on the grating, and a second prism moveable to finely select an angle of incidence of the light on the grating. In one application, the apparatus may be used as a line narrowing module for a laser light source.

Line selected F2 two chamber laser system

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in a F2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between ...

Extreme ultraviolet light source

A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light.

Six to ten KHz, or greater gas discharge laser system

The present invention provides gas discharge laser systems capable of reliable long-term operation in a production line capacity at repetition rates in the range of 6,000 to 10,0000 pulses power second. Preferred embodiments are configured as KrF, ArF and F₂ lasers used for light sources for integrated circuit lithography. Improvements include a modified high voltage power supply capable for charging an initial capacitor of a magnetic compression pulse power system to precise target voltages 6,000 to 10,0000 times per second and a feedback control for monitoring pulse energy and determining the target voltages on a pulse-by-pulse basis. Several techniques are disclosed for removing discharge created debris from the discharge region between the laser electrodes during the intervals between discharges. In one embodiment the width of the discharge region is reduced from about 3 mm to about 1 mm so that a gas circulation system designed for 4,000 Hz operation could be utilized for ...

Line Narrowing Module

An apparatus is disclosed which may comprise a grating receiving light, a first prism moveable to coarsely select an angle of incidence of the light on the grating, and a second prism moveable to finely select an angle of incidence of the light on the grating. In one application, the apparatus may be used as a line narrowing module for a laser light source.

Control system for a two chamber gas discharge laser

The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) F₂ injection controls with novel learning algorithm.

Method and apparatus for EUV plasma source target delivery

An EUV plasma formation target delivery system and method is disclosed which may comprise: a target droplet formation mechanism comprising a magneto-restrictive or electro-restrictive material, a liquid plasma source material passageway terminating in an output orifice; a charging mechanism applying charge to a droplet forming jet stream or to individual droplets exiting the passageway along a selected path; a droplet deflector intermediate the output orifice and a plasma initiation site periodically deflecting droplets from the selected path, a liquid target material delivery mechanism comprising a liquid target material delivery passage having an input opening and an output orifice; an electromotive disturbing force generating mechanism generating a disturbing force within the liquid target material, a liquid target delivery droplet formation mechanism having an output orifice; and/or a wetting barrier around the periphery of the output orifice.

Laser system

An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the second seed laser.

EXTREME ULTRAVIOLET LIGHT SOURCE

A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light. 1. A method of reducing back reflections in an extreme ultraviolet (EUV) light system , the method comprising:providing a target material that comprises a material that emits extreme ultraviolet light when converted to plasma and reflects light that propagates along a direction of propagation in a first direction;modifying a geometric distribution of the target material to form a modified target, the modified target comprising an optically reflective surface that reflects light that propagates along the direction of propagation in a second direction that is different from the first direction; anddirecting an amplified light beam from an optical source along the direction of propagation toward the reflective surface of the modified target, the amplified light beam converting at least part of the modified target to plasma that emits EUV light and producing a reflection of the amplified light beam that travels in the second direction, to thereby direct the reflection away from the source.2. The method of claim 1 , further comprising focusing the amplified light beam at a focal plane claim 1 , and wherein the modified target is outside of the focal plane.3. The method of claim 2 , wherein focusing the amplified light beam at a focal plane comprises forming a beam waist of the amplified light beam in a region claim 2 , and the modified ...

Four KHz gas discharge laser

The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Laser discharge chamber passivation by plasma

Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than ...

Laser system

A method/apparatus may comprise a laser light source which may comprise a solid state seed laser system producing a seed laser output having a nominal center wavelength at a pulse repetition rate; a first and a second gas discharge laser amplifier gain medium each operating at a pulse repetition rate less than that of the seed laser system; a beam divider providing each of the respective first and second amplifier gain mediums with seed laser output pulses; a frequency converter modifying the nominal center wavelength of the output of the seed laser to essentially the nominal center wavelength of the amplifier gain medium; a beam combiner combining the outputs of the respective amplifier gain mediums to provide a light source output having the pulse repetition rate of the seed laser; a coherence buster operating on either or both of the output of the seed laser or amplifier gain mediums.

System and Method for Protecting a Seed Laser in an EUV Light Source With a Bragg AOM

A method and apparatus for protecting the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed in one embodiment, a Bragg AOM is used as a switch on the beam path from the seed laser to other optical components and ultimately to an irradiation site. Power is applied to the Bragg AOM and pulses from the seed laser are thus deflected onto the desired beam path rather than passing straight through the Bragg AOM. Once the pulses have passed through the Bragg AOM, power to the Bragg AOM ceases, so that any reflections from the irradiation site will pass straight through the Bragg AOM and will not be deflected back to the seed laser. Use of the Bragg AOM rather than components previously used results in lower power consumption and better protection for the seed laser. 1. A system comprising:a laser source producing laser light on a first path;a Bragg acousto-optic modulation device switchable between a first state in which the laser light is deflected from the first path onto a second path toward an irradiation site at which a target material may be irradiated by the laser light and a second state in which the laser light is transmitted in a direction other than onto the second path;a delay device on the second path between the Bragg device and the irradiation site for delaying the laser light; andmeans for switching the Bragg device from the first state to the second state after the laser light has been deflected onto the second with such that any reflections of the laser light from the irradiation site are transmitted in a direction other than along the first path, and thus prevented from reaching the laser source.2. The system of wherein the laser source is a seed laser.3. The system of wherein the delay device comprises a folding optical arrangement.4. The system of wherein the delay device creates a delay in the transmission of the laser light to the irradiation site and any reflection of the laser light from the ...

Etalon testing system and process

The present invention provides a relatively simple etalon testing system and process for measuring cavity error of etalons to high precision. It works equally well on solid and air-spaced designs. This invention should be a great aid in the manufacture of high performance etalons, separating out the geometric and reflectivity finesses. The present invention permits measurement of etalon spacings to an accuracy of better than λ/1000 (i.e., about 63 picometers [6.3×10 −11 m] when using a HeNe test laser). In a preferred process an etalon under examination is mounted on a rotational stage illuminated with a collimated beam from a HeNe laser. Reflections from the etalon are imaged on a screen to produce interference fringes which are monitored by a CCD camera. The etalon is then pivoted about an axis perpendicular to the laser beam and images of the interference patterns are recorded periodically to produce a plot of intensity vs. pivot angle over a pivot range sufficient to include at least one extinction cycle. (Extinction occurs when the etalon is positioned at such an angle that interference in the etalon causes almost complete extinction of the reflected beam). The interference pattern, as a function of pivot angle, are then analyzed to determine the etalon spacing.

Laser wavelength control unit with piezoelectric driver

An electric discharge laser with fast wavelength correction. Fast wavelength correction equipment includes at least one piezoelectric drive and a fast wavelength measurement system and fast feedback response times. In a preferred embodiment, equipment is provided to control wavelength on a slow time frame of several milliseconds, on a intermediate time from of about one to five milliseconds and on a very fast time frame of a few microseconds. Preferred techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver for tuning the laser wavelength using a tuning mirror. A preferred control technique is described (utilizing a very fast wavelength monitor) to provide the slow and intermediate wavelength control with the combination of a stepper motor and a piezoelectric driver. Very fast wavelength control is provided with a piezoelectric load cell in combination with the piezoelectric driver. Preferred embodiments provide (1) fast feedback control ...

Laser system

A method/apparatus may comprise a laser light source which may comprise a solid state seed laser system producing a seed laser output having a nominal center wavelength at a pulse repetition rate; a first and a second gas discharge laser amplifier gain medium each operating at a pulse repetition rate less than that of the seed laser system; a beam divider providing each of the respective first and second amplifier gain mediums with seed laser output pulses; a frequency converter modifying the nominal center wavelength of the output of the seed laser to essentially the nominal center wavelength of the amplifier gain medium; a beam combiner combining the outputs of the respective amplifier gain mediums to provide a light source output having the pulse repetition rate of the seed laser; a coherence buster operating on either or both of the output of the seed laser or amplifier gain mediums.

Lithography laser with beam delivery and beam pointing control

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source with a beam delivery to a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. Preferred embodiments include equipment for beam attenuation, equipment for automatic feedback beam alignment and equipment for accurate optics module positioning at installation and during maintenance. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout the operating life of the lithography system, despite substantial degradation of optical components.

Injection seeded F2 laser with pre-injection filter

A narrow band F2 laser system useful for integrated circuit lithography. An output beam from a first F2 laser gain medium is filtered with a pre-gain filter to produce a seed beam having a bandwidth of about 0.1 pm or less. The seed beam is amplified in a power gain stage which includes a second F2 laser gain medium. The output beam of the system is a pulsed laser beam with a full width half maximum band width of about 0.1 pm or less with pulse energy in excess of about 5 mJ. In a preferred embodiment the pre-gain filter includes a wavelength monitor which permits feedback control over the centerline wavelength so that the pre-gain filter optics can be adjusted to ensure that the desired bandwidth range is injected into the power gain stage.

High power seed/amplifier laser system with beam shaping intermediate the seed and amplifier

An apparatus and method of operation for a high power broad band elongated thin beam laser annealing light source, which may comprise a gas discharge seed laser oscillator having a resonance cavity, providing a seed laser output pulse; a gas discharge amplifier laser amplifying the seed laser output pulse to provide an amplified seed laser pulse output; a divergence correcting multi-optical element optical assembly intermediate the seed laser and the amplifier laser. The divergence correcting optical assembly may adjust the size and/or shape of the seed laser output pulse within a discharge region of the amplifier laser in order to adjust an output parameter of the amplified seed laser pulse output. The divergence correcting optical assembly may comprise a telescope with an adjustable focus. The adjustable telescope may comprise an active feedback-controlled actuator based upon a sensed parameter of the amplified seed laser output from the amplifier laser.

Extreme ultraviolet light source

A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light.

Laser system

A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

Very narrow band, two chamber, high rep rate gas discharge laser system

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in an ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds ...

Very narrow band, two chamber, high reprate gas discharge laser system

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in an ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between pulses. The master oscillator is equipped with a line narrowing package having a very fast tuning mirror capable of controlling centerline wavelength on a pulse-to-pulse basis at repetition rates of 4000 Hz or greater to a precision of less than 0.2 pm.

Very narrow band, two chamber, high rep-rate gas discharge laser system

An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected ...

Regenerative ring resonator

A laser includes a regenerative ring resonator that includes a discharge chamber having electrodes and a gain medium between the electrodes for producing a laser beam; a partially-reflective optical coupler, and a beam modification optical system in the path of the laser beam. The beam modification optical system transversely expands a profile of the laser beam such that the near field laser beam profile uniformly fills each aperture within the laser and such that the regenerative ring resonator remains either conditionally stable or marginally unstable when operating the laser at powers that induce thermal lenses in optical elements inside the regenerative ring resonator.

System and method for protecting a seed laser in an EUV light source with a Bragg AOM

A method and apparatus for protecting the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed in one embodiment, a Bragg AOM is used as a switch on the beam path from the seed laser to other optical components and ultimately to an irradiation site. Power is applied to the Bragg AOM and pulses from the seed laser are thus deflected onto the desired beam path rather than passing straight through the Bragg AOM. Once the pulses have passed through the Bragg AOM, power to the Bragg AOM ceases, so that any reflections from the irradiation site will pass straight through the Bragg AOM and will not be deflected back to the seed laser. Use of the Bragg AOM rather than components previously used results in lower power consumption and better protection for the seed laser.

Laser spectral engineering for lithographic process

An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond. In a preferred embodiment, a wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second ...

EUV light source with subsystem(s) for maintaining LPP drive laser output during EUV non-output periods

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet.

High repetition rate laser produced plasma EUV light source

An EUV light source apparatus and method are disclosed, which may comprise a pulsed laser providing laser pulses at a selected pulse repetition rate focused at a desired target ignition site; a target formation system providing discrete targets at a selected interval coordinated with the laser pulse repetition rate; a target steering system intermediate the target formation system and the desired target ignition site; and a target tracking system providing information about the movement of target between the target formation system and the target steering system, enabling the target steering system to direct the target to the desired target ignition site. The target tracking system may provide information enabling the creation of a laser firing control signal, and may comprise a droplet detector comprising a collimated light source directed to intersect a point on a projected delivery path of the target, having a respective oppositely disposed light detector detecting the passage of the ...

Multi-pass optical apparatus

An apparatus includes a first plurality of concave reflecting surfaces; a second plurality of reflecting surfaces facing the first plurality of concave reflecting surfaces such that a region is defined between the first and second pluralities; and an input for an optical beam to enter the region and an output for the optical beam to exit the region. The first and second pluralities of reflecting surfaces are arranged relative to each other so that the optical beam is re-imaged at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities and so that overlap of two or more optical beams on each of the reflecting surfaces is avoided.

Master oscillator-power amplifier drive laser with pre-pulse for EUV light source

A device is described herein which may comprise an optical amplifier having a gain band including wavelengths λ 1 and λ 2 , with λ 1 ≠λ 2 ; a pre-pulse seed laser having a tuning module for tuning a pre-pulse output to wavelength λ 1 ; a main pulse seed laser generating a laser output having wavelength, λ 2 ; and a beam combiner for directing the pre-pulse output and the main pulse output on a common path through the optical amplifier.

Multi-Pass Optical Apparatus

An apparatus includes a first plurality of concave reflecting surfaces; a second plurality of reflecting surfaces facing the first plurality of concave reflecting surfaces such that a region is defined between the first and second pluralities; and an input for an optical beam to enter the region and an output for the optical beam to exit the region. The first and second pluralities of reflecting surfaces are arranged relative to each other so that the optical beam is re-imaged at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities and so that overlap of two or more optical beams on each of the reflecting surfaces is avoided. 1. A method comprising: re-imaging the optical beam at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities; and', 'avoiding overlap of two or more optical beams on each of the reflecting surfaces of both of the pluralities., 'reflecting an optical beam back and forth between reflecting surfaces of a first plurality of reflecting surfaces and reflecting surfaces of a second plurality of reflecting surfaces, the reflecting including2. The method of claim 1 , wherein reflecting the optical beam back and forth between reflecting surfaces of the first plurality of reflecting surfaces and reflecting surfaces of the second plurality of reflecting surfaces includes re-imaging the optical beam from a first reflecting surface of the first plurality onto a second reflecting surface of the first plurality.3. The method of claim 2 , wherein re-imaging the optical beam from the first reflecting surface of the first plurality onto the second reflecting surface of the first plurality includes reflecting the optical beam from a reflecting surface of the second plurality.4. The method of claim 2 , wherein the second reflecting surface of the first plurality on which the optical beam is re-imaged is adjacent ...

Control system for a two chamber gas discharge laser system

The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Feedback timing control techniques are provided for controlling the relative timing of the discharges in the two chambers with an accuracy in the range of about 2 to 5 billionths of a second even in burst mode operation. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality.

HIGH POWER HIGH PULSE REPETITION RATE GAS DISCHARGE LASER SYSTEM

A method of line narrowing for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses includes selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on a dispersive surface of a dispersive wavelength selection optic; changing the curvature of the dispersive surface in a first manner that includes imparting a catenary curvature to the dispersive surface; and changing the curvature of the dispersive surface in a second manner that includes imparting a cylindrical curvature to the dispersive surface.

EXTENDABLE ELECTRODE FOR GAS DISCHARGE LASER

A movable electrode assembly for use in a laser system, includes a first electrode having a first discharge surface, a second electrode having a second discharge surface. The second electrode being arranged opposite from the first electrode. The second discharge surface being spaced apart from the first discharge surface by a discharge gap. A discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A method of adjusting a discharge gap is also disclosed.

F2 laser with visible red and IR control

A reliable, modular, production quality F 2 excimer laser capable of producing, at repetition rates in the range of 1,000 to 2,000 Hz or greater, laser pulses with pulse energies greater than 10 mJ with a full width half, maximum bandwidth of about 1 pm or less at wavelength in the range of 157 nm. Laser gas concentrations are disclosed for reducing unwasted infrared emissions from the laser. Also disclosed are UV energy detectors which are substantially insensitive to infrared light. Preferred embodiments of the present invention can be operated in the range of 1000 to 4000 Hz with pulse energies in the range of 10 to 5 mJ with power outputs in the range of 10 to 40 watts. Using this laser as an illumination source, stepper or scanner equipment can produce integrated circuit resolution of 0.1 μm or less. Replaceable modules include a laser chamber and a modular pulse power system.

System and method for seed laser mode stabilization

A method and apparatus for stabilizing the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed. In one embodiment, the cavity length of the laser may be adjusted by means of a movable mirror forming one end of the cavity. The time delay from the release of an output pulse to the lasing threshold next being reached is measured at different mirror positions, and a mirror position selected which results in a cavity mode being aligned with the gain peak of the laser, thus producing a minimum time delay from an output pulse of the laser to the next lasing threshold. A Q-switch in the laser allows for pre-lasing and thus jitter-free timing of output pulses. Feedback loops keep the laser output at maximum gain and efficiency, and the attenuation and timing at a desired operating point.

Laser lithography light source with beam delivery

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout ...

Line narrowing module

A line narrowing method and module for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses, the module having a nominal optical path are disclosed which may comprise: a dispersive center wavelength selection optic moveably mounted within an optical path of the line narrowing module, selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a first tuning mechanism operative in part to select the angle of incidence of the laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic, by selecting an angle of transmission of the laser light pulse beam containing the pulse toward the dispersive center wavelength selection optic; a second tuning mechanism operative in part to select the angle of incidence ...

Laser Produced Plasma EUV Light Source

A device is disclosed herein which may include a plasma generating system comprising a source of target material droplets and a laser producing a beam irradiating the droplets at an irradiation region, the plasma producing EUV radiation, wherein the droplet source comprises a fluid exiting an orifice and a sub-system producing a disturbance in the fluid which generates droplets having differing initial velocities causing the spacing between at least some adjacent droplets to decrease as the droplets travel to the irradiation region.

High resolution etalon-grating monochromator

A high resolution etalon-grating monochromator. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light passing through the slit is collimated and the collimated light illuminates a grating positioned in an approximately Littrow configuration which disburses the light according to wavelength. A portion of the dispursed light representing the wavelength corresponding to the selected etalon fringe is passed through a second slit and monitored by a light detector. When the etalon and the grating are tuned to the same precise wavelength a slit function is defined which is extremely narrow such as about ...

EUV light source with subsystem(s) for maintaining LPP drive laser output during EUV non-output periods

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet.

LASER SYSTEM

An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½X kHz on output pulses from the second seed laser.

Laser lithography light source with beam delivery

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout ...

Wavemeter for gas discharge laser

An optical configuration to illuminate an etalon in a laser wavemeter with a minimum level of light intensity. The system includes optical components to direct a portion of the laser output beam representing the entire cross section of the beam, through an etalon positioned in an etalon housing and onto a photodetector. A first lens condenses the size of the beam sample, and a second lens re-collimates the beam which then passes into the etalon housing, ensuring that all of the spatial components of the beam are adequately sampled. A diffractive diffusing element is incorporated into the optical path. In a preferred embodiment, the diffractive diffusing element is placed within the etalon housing between said plano-concave lens and the etalon. In another preferred embodiment, the diffusing element is located up stream but outside the housing in the optical path.

Extreme repetition rate gas discharge laser

A gas discharge laser capable of operating at pulse rates in the range of 4,000 Hz to 6,000 Hz at pulse energies in the range of 5 mJ to 10 mJ or greater. Important improvements over prior art designs include: (1) a laser chamber having a gas flow path with a gradually increasing cross section downstream of the discharge electrodes to permit recovery a large percentage of the pressure drop in the discharge region, (2) a squirrel cage type fan for producing gas velocities through the discharge region of more than 76 m/s and capable of continuous trouble-free operation for several months, (3) a heat exchanger system capable of removing in excess of 16 kw of heat energy from the laser gas (4) a pulse power system capable of providing precisely controlled electrical pulses to the electrodes needed to produce laser pulses at the desired pulse energies in the range of 5 mJ to 10 mJ or greater at pulse repetition rates in the range of 4,000 Hz to 6,000 Hz or greater and (5) a laser beam measurement ...

Line selected F2 two chamber laser system

An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in a F 2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between pulses. The master oscillator is equipped with a line selection package for selecting the strongest F 2 spectral line.

Laser spectral engineering for lithographic process

An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond. In a preferred embodiment, a wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second ...

Bandwidth control technique for a laser

A technique for bandwidth control of an electric discharge laser. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection means and a bandwidth control having a time response of less than about 1.0 millisecond. In a preferred embodiment wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second within a very narrow range of pivot angles to cause a dither in nominal wavelength values to produce a desired effective bandwidth of series of laser pulses.

EUV LIGHT SOURCE WITH SUBSYSTEM(S) FOR MAINTAINING LPP DRIVE LASER OUTPUT DURING EUV NON-OUTPUT PERIODS

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet. 1. A device comprising:a droplet generator producing droplets of target material;a sensor providing an intercept time signal when a droplet reaches a preselected location;a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal;a laser source responsive to a trigger signal to produce a laser pulse; anda system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet.2. The device as recited in wherein the first delay time is longer than the second delay time.3. The device as recited in wherein the first delay time is shorter than the second delay time.4. The device as recited in wherein the sensor comprises a laser source and a detector.5. The device as recited in wherein the delay circuit comprises a digital shift register.6. A method for producing EUV pulses in at least two burst periods claim 1 , the burst periods separated by an intervening period claim 1 , the method comprising the steps of:generating target material droplets during each burst ...

OSCILLATOR-AMPLIFIER DRIVE LASER WITH SEED PROTECTION FOR AN EUV LIGHT SOURCE

As disclosed herein, in a first aspect, a device may comprise: an oscillator producing a light output on a beam path; a target material for interaction with light on the beam path at an irradiation site; a beam delay on the beam path the beam delay having a beam folding optical arrangement; and a switch positioned along the beam path and interposed between the oscillator and the beam delay; the switch closable to divert at least a portion of light on the beam path from the beam path, the switch having close time, tand the beam path having a length, L, along the path from the switch to the irradiation site; with t Подробнее

EUV Light Source With Subsystem(s) For Maintaining LPP Drive Laser Output During EUV Non-Output Periods

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet. 1a droplet generator producing droplets of target material;a sensor providing an intercept time signal when a droplet reaches a preselected location;a delay circuit coupled with said sensor, the delay circuit generating, responsive to at least burst timing input from an exposure tool control system, a trigger signal delayed from the intercept time signal;a laser source responsive to a trigger signal to produce a laser pulse; anda system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which does not impinge upon a droplet.. A device comprising; The present application is a continuation of U.S. patent application Ser. No. 13/157,233, filed on Jun. 9, 2011, and published on Apr. 5, 2012, as US-2012-0080584-A1, entitled EUV LIGHT SOURCE WITH SUBSYSTEM(S) FOR MAINTAINING LPP DRIVE LASER OUTPUT DURING EUV NON-OUTPUT PERIODS, Attorney Docket Number 2010-0014-02, which claims the benefit of U.S. Provisional Application Ser. No. 61/404,564, filed on Oct. 4, 2010, entitled EUV LIGHT SOURCE WITH A TEMPERATURE STABILIZED DRIVE LASER, Attorney Docket Number ...

EXTREME ULTRAVIOLET LIGHT SOURCE

A target material is provided at a target location, the target material including a material that emits extreme ultraviolet light when converted to plasma, and the target material extending in a first extent along a first direction and in a second extent along a second direction; an amplified light beam is directed along a direction of propagation toward the target location; and the amplified light beam is focused in a focal plane, where the target location is outside of the focal plane and an interaction between the amplified light beam and the target material converts at least part of the target material to plasma that emits EUV light. 1. Method comprising:directing a target along a target path toward a target location in a vacuum chamber, the target comprising target material in a geometric distribution that comprises a first extent along a first direction, and a second extent along a second direction, the first and second direction being orthogonal directions, the first extent and the second extent being different, the target material emitting extreme ultraviolet (EUV) light when in a plasma state; anddirecting an amplified light beam toward the target location, the amplified light beam traveling along a propagation path and having an energy sufficient to convert at least some of the target material in the target to a plasma that emits EUV light, whereinthe propagation path and the target path are non-orthogonal at the target location.2. The method of claim 1 , whereinthe second extent is greater than the first extent,the target comprises a region that receives the amplified light beam, the region extending in the second direction, andthe propagation path and the first direction are non-orthogonal at the target location.3. The method of claim 2 , wherein the geometric distribution of the target material is substantially disk shaped.4. The method of claim 3 , wherein the target path is along the second direction at the target location.5. The method of claim 1 , ...

EUV LIGHT SOURCE WITH SUBSYSTEM(S) FOR MAINTAINING LPP DRIVE LASER OUTPUT DURING EUV NON-OUTPUT PERIODS

A device is disclosed herein which may comprise a droplet generator producing droplets of target material; a sensor providing an intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the intercept time signal; a laser source responsive to a trigger signal to produce a laser pulse; and a system controlling said delay circuit to provide a trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light pulse which is not focused on a droplet. 1. An Extreme Ultraviolet (EUV) light source producing EUV pulses in at least two burst periods , the at least two burst periods separated by an intervening period , the EUV light source comprising:a droplet generator producing droplets of target material during each of the at least two burst periods and during the intervening period;a laser source producing laser pulses during the each of the at least two burst periods and during the intervening period; anda system operable to reconfigure the EUV light source from a first configuration in which the laser pulses generated during the each of the at least two burst periods interact with the droplets of target material to produce a plasma having first characteristics and a second configuration in which laser pulses generated during the intervening period do not produce the plasma having the first characteristics.2. The EUV light source of wherein the laser pulses generated during the intervening period produces plasma having second characteristics different from the first characteristics.3. The EUV light source of wherein the laser pulses generated during the intervening period do not produce plasma.4. The EUV light source of wherein the target material is subject to a first disturbance during the each of the at ...

Wavelength shift correction technique for a laser

A wavelength shift correction system for a laser system is provided for correcting wavelength chirps. This wavelength shift correction system includes a learning algorithm that learns characteristics of a wavelength chirp from a laser and a computer system that executes the learning algorithm and provides wavelength correction control signals based on the learned characteristics to reduce the magnitude of the wavelength shift of the present wavelength chirp and subsequent wavelength chirps.

Master oscillator—power amplifier drive laser with pre-pulse for EUV light source

A device is described herein which may comprise an optical amplifier having a gain band including wavelengths λ 1 and λ 2 , with λ 1 ≠λ 2 ; a pre-pulse seed laser having a tuning module for tuning a pre-pulse output to wavelength λ 1 ; a main pulse seed laser generating a laser output having wavelength, λ 2 ; and a beam combiner for directing the pre-pulse output and the main pulse output on a common path through the optical amplifier.

Method and apparatus for EUV plasma source target delivery

An EUV plasma formation target delivery system and method is disclosed which may comprise: a target droplet formation mechanism comprising a magneto-restrictive or electro-restrictive material, a liquid plasma source material passageway terminating in an output orifice; a charging mechanism applying charge to a droplet forming jet stream or to individual droplets exiting the passageway along a selected path; a droplet deflector intermediate the output orifice and a plasma initiation site periodically deflecting droplets from the selected path, a liquid target material delivery mechanism comprising a liquid target material delivery passage having an input opening and an output orifice; an electromotive disturbing force generating mechanism generating a disturbing force within the liquid target material, a liquid target delivery droplet formation mechanism having an output orifice; and/or a wetting barrier around the periphery of the output orifice.

Extendable electrode for gas discharge laser

Disclosed herein are systems and methods for extending one or both of the discharge electrodes in a transverse discharge gas laser chamber in which one or both the electrodes are subject to a dimensional change due to erosion. Electrode extension can be performed to increase the chamber life, increase laser performance over the life of the chamber, or both. Operationally, the inter-electrode spacing may be adjusted to maintain a specific target gap distance between the electrodes or to optimize a specific parameter of the laser output beam such as bandwidth, pulse-to-pulse energy stability, beam size, etc.

Extendable electrode for gas discharge laser

A movable electrode assembly for use in laser system includes a first electrode, a second electrode arranged opposite from the first electrode, the second electrode being spaced apart from the first electrode by a discharge gap and a discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A movable electrode assembly for integration into a housing of a laser system includes a first electrode having a discharge surface, a second electrode having a discharge surface, such that the discharge surface of the first electrode and the discharge surface of the second electrode face each other in a spaced apart setting that defines a desired discharge gap, and a mechanism for moveably adjusting the spaced apart setting toward the desired discharge gap. A method of adjusting a discharge gap is also disclosed.

Manufacture of semiconductor element

(57)【要約】 【課題】 本発明の目的はエキシマレーザーを必要な波 長の出力光に正確にチューニングする技術を提供するこ とにある。 【解決手段】 チューニング可能なレーザーに用いられ る波長測定器をキャリブレートするための絶対的な波長 基準として、既知の原子又は分子の吸収線を用いる。波 長器には吸収ガスを含むガスセルが装備されており、キ ャリブレーションの間に、測定された波長が原子あるい は分子の吸収線と比較され、波長器のキャリブレーショ ン定数は絶対的な水準にキャリブレートされ。酸素分子 のようないくつかのガスは、レーザーのチューニング可 能範囲に複数分子吸収線を持っており、これを利用すれ ば目的の最終波長の精度が増す。

Plasma focus light source with active and buffer gas control

A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. The chamber contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at repetition rates of 1000 Hz or greater and at voltages high enough to create electrical discharges between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the source or active gas. A fourth generation unit is described which produces 20 mJ, 13.5 nm pulses into 2 π steradians at repetition rates of 2000 Hz with xenon as the active gas. This unit includes a pulse power system having a resonant charger charging a charging capacitor bank, and a magnetic compression circuit comprising a pulse transformer for generating the high voltage electrical pulses at repetition rates of 2000 Hz or greater. Gas flows in the vacuum chamber are controlled to assure desired concentration of active gas in the discharge region and to minimize active gas concentration in the beam path downstream of the pinch region. In a preferred embodiment, active gas is injected downstream of the pinch region and exhausted axially through the center of the anode. In another preferred embodiment a laser beam generates metal vapor at a location close to but downstream of the pinch region and the vapor is exhausted axially through the anode.

Lithographic projection apparatus equipped with extreme ultraviolet window serving simultaneously as vacuum window

A lithographic projection apparatus has a discharge plasma radiation source that is contained in a vacuum chamber. The radiation source is to generate a beam of EUV radiation. A chamber wall of the vacuum chamber incorporates a channel structure comprising adjacent narrow channels separated by walls that are substantially parallel to a propagation direction of the radiation generated so as to pass the radiation from the vacuum chamber through the structure to another subsequent vacuum chamber. In the subsequent vacuum chamber, a much higher vacuum level (lower pressure) can be maintained than is present in the vacuum chamber of the radiation source.

Laser wavelength control unit with piezoelectric driver

An electric discharge laser (34) with fast wavelength correction. Fast wavelength correction equipment includes at least one piezoelectric drive and a fast wavelength measurement system (104) and fast feedback response times. In a preferred embodiment, equipment is provided to control wavelength on a slow time frame of several milliseconds, on a intermediate time from of about one to five milliseconds and on a very fast time frame of a few microseconds. Preferred techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver for tuning the laser wavelength using a tuning mirror. Very fast wavelength control is provided with a piezoelectric load cell in combination with the piezoelectric driver. Preferred embodiments provide fast feedback control based on wavelength measurements, fast vibration control, active damping using the load cell and an active damping module (320), and transient inversion using feed forward algorithms based on historical burst data.

Plasma focus light source with active and buffer gas control

A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber (10). The chamber (10) contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at repetition rates of 1000 Hz or greater and at voltages high enough to create electrical discharge between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the source or active gas. A fourth generation unit is described which produces 20 mJ, 13.5 nm pulses into 2 pi steradians at repetition rates of 2000 Hz with xenon as the active gas. This unit includes a pulse power system having a resonant charger charging a charging capacitor bank, and a magnetic compression circuit comprising a pulse transformer for generating the high voltage electrical pulses at 2000 Hz or greater. Gas flows in the vacuum chamber are controlled to assure desired concentration of active gas in the discharge region and to minimize active gas concentration in the beam path downstream of the pinch region. In a preferred embodiment, active gas is injected downstream of the pinch region through a nozzle (2) and exhausted axially through an exhaust port (3) in the center of the anode. In another preferred embodiment a laserbeam generates metal vapor at a location close to but downstream of the pinch region and the vapor is exhausted axially through the anode.

Excimer laser with greater spectral bandwidth and beam stability

Reliable. modular, production quality narrow-band KRF excimer laser

A reliable, modular, production quality narrow-band KrF excimer laser capable of producing 10 mJ laser pulses at 1000 Hz with a bandwidth of about 0.6 pm or less. The present invention is especially suited to long-term round-the-clock operation in the lithographic production of integrated circuits. Improvements over prior art lasers include a single upstream preionizer tube and acoustic baffles. A preferred embodiment includes reduced fluorine concentration, an anode support bar shaped to reduce aerodynamic reaction forces on blower bearings, a modified pulse power system providing faster pulse rise time, an output coupler with substantially increased reflectivity, a line narrowing module with CaF prism beam expanders, a more accurate wavemeter, a laser computer controller programmed with new and improved pulse energy control algorithm.

High power gas discharge laser with helium purged line narrowing unit

A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the use of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating (16). In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Multi-pass optical apparatus

An apparatus includes a first plurality of concave reflecting surfaces; a second plurality of reflecting surfaces facing the first plurality of concave reflecting surfaces such that a region is defined between the first and second pluralities; and an input for an optical beam to enter the region and an output for the optical beam to exit the region. The first and second pluralities of reflecting surfaces are arranged relative to each other so that the optical beam is re-imaged at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities and so that overlap of two or more optical beams on each of the reflecting surfaces is avoided.

Injection seeded f2 lithography laser

The claimed invention is a tunable injection seeded very narrow band F2 lithography laser. The laser combines modular design features of prior art long life releasable lithography lasers with special F2 line narrowing and tuning techniques. This techniques are applied to a seed beam which is operated in a first gain medium. This seed beam is then used to stimulate narrow band lasing in a second gain medium. The resulting very narrow band laser beam is useful for integrated circuit lithography. One preferred embodiment of the invention comprises a laser chamber (211), a gas module (202), a control module (205), a line narrowing module (206), and a pulse power supply module (208).

Laser wavelength control unit with piezoelectric driver

An electric discharge laser with fast wavelength correction. Fast wavelength correction equipment includes at least one piezoelectric drive and a fast wavelength measurement system and fast feedback response times. In a preferred embodiment, equipment is provided to control wavelength on a slow time frame of several milliseconds, on a intermediate time from of about one to three millisecond and on a very fast time frame of a few microseconds. Techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver for tuning the laser wavelength using a tuning mirror. A preferred control technique is described (utilizing a very fast wavelength monitor) to provide the slow and intermediate wavelength control and a piezoelectric load cell in combination with the piezoelectric driver to provide the very fast (few microseconds) wavelength control.

Method for lpp drive laser output during euv non-output periods

Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby

Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby which avoids the necessity of maintaining a good vacuum in the wave meter housing and which provides the quick establishment of wave length accuracy after laser turn on before temperature stability in the wave meter is reached. In accordance with the method, the wave meter housing is filled preferably with one atmosphere of dry nitrogen, and the wave meter output is corrected for temperature effects by combining the uncorrected or raw wave meter output with an appropriate wave meter temperature dependent component and an additional appropriate rate of change of wave meter temperature dependent component. The net result is the achievement of accuracy and stability in the wave meter output without use of an oven and before a steady state operating temperature is attained.

Excimer laser with greater spectral bandwidth and beam stability

Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby

Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby which avoids the necessity of maintaining a good vacuum in the wave meter housing and which provides the quick establishment of wavelength accuracy after laser turn on before temperature stability in the wave meter is reached. In accordance with the method, the wave meter housing (12) is filled preferably with one atmosphere of dry nitrogen, and the wave meter output is corrected for temperature effects by combining the uncorrected or raw wave meter output with an appropriate wave meter temperature dependent component (14) and an additional appropriate rate of change of wave meter temperature dependent component (16). The net result is the achievement of accuracy and stability in the wave meter output without use of an oven and before a steady state operating temperature is attained.

Systems and methods for implementing an interaction between a laser shaped as a line beam and a film deposited on a substrate

Systems and methods to shape laser light as a homogeneous line beam for interaction with a film deposited on a substrate

Method and apparatus for eliminating reflected energy due to stage mismatch in nonlinear magnetic compression modules

A high voltage pulse power generating circuit capable of eliminating secondary pulses due to stage mismatch in the stages of its magnetic pulse compressor circuit is disclosed. The pulse generating circuit source comprises a high voltage charge storing element which is periodically discharged into a nonlinear magnetic compressor circuit. A mismatch correction circuit coupled to each stage of the compressor circuit discharges the reflected energy due to stage mismatch and thus eliminates the reflected energy from being launched back into the load. In a preferred embodiment, the pulse power generating circuit of the present invention utilizes a diode and a resistor that is coupled to each stage of the magnetic pulse compressor circuit. Various embodiments are disclosed.

Method for lpp drive laser output during euv non-output periods

A device is disclosed, herein which may comprise a droplet generator producing droplets of target material; a sensor providing an. intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the. intercept time signal; a. laser source responsive to a trigger signal to produce a laser pulse-; and a system controlling said delay circuit to provide a. trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light -pulse which is not focused on a droplet.

Systems and methods to shape laser light as a homogeneous line beam for interaction with a film deposited on a substrate

Systems and methods are disclosed for shaping and homogenizing a laser beam for interaction with a film. The shaping and homogenizing system may include a lens array and a lens that is positioned to receive laser light from the lens array and produce a respective elongated image in a plane for each lens in the lens array. In addition, the system may include a beam stop having an edge that is positioned in the plane, and a moveable mount rotating a lens of the lens array to vary an alignment between one of the elongated images and the beam stop edge.

Reliable, modular, production quality narrow-band krf excimer laser

Wavelength shift correction technique for a laser

A wavelength shift correction system for a laser system is provided for correcting wavelength chirps. This wavelength shift correction system includes a learning algorithm (44) that learns characteristics of a wavelength chirp from a laser (34) and a computer system (46) that executes the learning algorithm and provides wavelength correction control signals based on the learned characteristics to reduce the magnitude of the wavelength shift of the present wavelength chirp and subsequent wavelength chirps.

Fast wavelength correction technique for a laser

Electric discharge laser with fast chirp correction. Fast wavelength chirp correction equipment includes at least one piezoelectric drive and a fast wavelength detection means and has a feedback response time of less than 1.0 millisecond. In a preferred embodiment a simple learning algorithm is described to allow advance tuning mirror adjustment in anticipation of the learned chirp pattern. Techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver. In another preferred embodiment chirp correction is made on a pulse-to-pulse basis where the wavelength of one pulse is measured and the wavelength of the next pulse is corrected based on the measurement. This correction technique is able to function at repetition rates as rapid as 2000 Hz and greater.

F2 dual-chamber laser system with line selection

High power gas discharge laser with helium purged line narrowing unit

A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beam s at high repetition rates. Applicants have shown substantial improvement in performance with the use of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across t he face of the grating (16). In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Laser discharge chamber passivation by plasma

A high repetition rate laser produced plasma EUV light source

Very narrow band, two chamber, high rep rate gas discharge laser system

An injection seeded modular gas discharge laser system (2) capable of producing high quality pulsed beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator (10) producing a very narrow band seed beam, which is amplified (12) in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in the ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan (10A) providing sufficient gas flow to permit operation at pulse rates of 4,000 Hz or greater by cleaning debris from the discharge region in less time that the approximately 0.25 milliseconds between pulses. The masters oscillation is equipped with a line narrowing package having a very fast tuning mirror capable of controlling centerline wavelength on a pulse-to-pulse basis at repetition rates of 4000 Hz or greater to a precision of less than 0.2 pm.

RELIABLE MODULAR PRODUCTION QUALITY NARROW-BAND HIGH REP RATE ArF EXCIMER LASER

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz with a full width half maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber (211), a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module (206) and an output coupler module (216); a wavemeter module (213), an electrical control module (205), a cooling water module (203) and a gas control module (202). Improvements in the pulse power unit to produce faster rise time and improved pulse energy control include: an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module (209) that generates a high voltage pulse from the capacitors charged by the high voltage power supply (20) and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. The compression head (207) saturable inductor greatly reduces the quantity of oil required and virtually eliminates the possibility of oil leakage.

Oscillator-amplifier drive laser with seed protection for an euv light source

As disclosed herein, in a first aspect, a device may comprise; an oscillator producing a light output on a beam path; a target material for interaction with Light on the beam path at an irradiation site; a beam delay on the beam path the beam delay haying a beam folding optical arrangement; and a switch positioned along the beam, path and Interposed between the oscillator and the beam delay; the switch closable to divert at. least a portion of light on the beam path from the beam path, the switch having close time, t 1 and the beam path having a Length, L 1 . along the path from the switch to the irradiation site; with t 1 < cL 1 , where e is the speed of light on the path, to protect the oscillator.

Plasma focus light source with tandem ellipsoidal mirror units

A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. The chamber contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at repetition rates of 1000 Hz or greater and at voltages high enough to create electrical discharges between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the source or active gas. A fourth generation unit is described which produces 20 mJ, 13.5 nm pulses into 2 π steradians at repetition rates of 2000 Hz with xenon as the active gas. This unit includes a pulse power system having a resonant charger charging a charging capacitor bank, and a magnetic compression circuit comprising a pulse transformer for generating the high voltage electrical pulses at repetition rates of 2000 Hz or greater.

Control system for a two chamber gas discharge laser

Extendable electrode for gas discharge laser

Compact excimer laser including an electrode mounted in insulating relationship to wall of the laser

A compact excimer laser, including a housing structure having a plurality of walls forming an internal laser cavity. A gas is located within the laser cavity and with the gas capable of lasing action. A pair of spaced electrodes are located within the laser cavity and form an electrical discharge area between the electrodes for stimulating gas within the discharge area to lasing action in accordance with an electrical discharge between the electrodes. One of the pair of electrodes is located along a central position within the cavity and is grounded to the housing structure. The other of the pair of electrodes is located adjacent to but spaced from one of the walls of the housing structure and with the other electrode mounted on a main insulator member. The main insulator member is formed of ceramic material and is located intermediate to the one wall of the housing and the other electrode but is spaced from the one wall of the housing to have the main insulator member floating relative to the housing structure. The main ceramic insulator member is compressively supported at a central position of the member and extends outward from this central position without any additional support to have the floating main insulator respond to any bending forces within the laser without any constraint other than the central support.

Fast wavelength correction technique for a laser

Pulse energy control for excimer laser

Line narrowing module

A line narrowing module (28) for a gas discharge laser producing a pulsed light beam comprising: a grating (22) mounted along an optical path of the line narrowing module (28), selecting at least one center wavelength for the pulsed light beam as determined at least in part by an angle of incidence of the pulsed light beam on the grating (22); a beam expander prism assembly (64) comprising three or more prisms (82, 84, 86, 88) including: a first prism ( 82)moveable to select an angle of incidence of the pulsed light beam on the grating (22) and having a relatively larger impact on the angle of incidence; and a second prism (84) moveable to select an angle of incidence of the pulsed light beam on the grating (22) and having a relatively smaller impact on the angle of incidence; wherein the first prism (82) has a magnification that is larger than the magnification of the second prim (84); and a controller configured to control the movement of the first (82) and second (84) prisms based on feedback from a center wavelength detector that detects a center wavelength of the pulsed light beam.

Laser-illuminated stepper or scanner with energy sensor feedback

A laser-illuminated wafer-exposing system such as a stepper (20) or scanner having a first light intensity detector (44) located within the exposing system near a mask (36) and second light intensity detector (46) located near the output of the laser (12). A feedback control system (14) controls the output of the laser based on signals detected by at least one of the detectors. The feedback control system includes a processor programmed with an algorithm which is used to control the laser discharge voltage in order to provide light pulses having desired intensity at the mask with the laser operating in a burst mode. The algorithm utilizes at least the following parameters; a previously measured pulse energy, a calculated energy error, a calculated dose error, a value for the rate of change of pulse energy with voltage, and at least one reference voltage. In a preferred embodiment the algorithm uses the pulse energy measured with the light intensity detector located near the mark to provide the feedback control and uses the light intensity detector at the output of the laser to assure that the output of the laser is maintained within a predetermined range.

High voltage cable interlock circuit

A low level current travels from a source through the high voltage cable (40) from the remote end to the local end of the cable (40) in a pulse power circuit. The current is detected and a signal is generated by a bias sensing circuit (118). If the low level current is not positively detected, no pulse is allowed to occur, preventing accidental damage and high voltage hazard. In some embodiments, the current is coupled to ground at the local end through an isolation inductor (46), commonly a secondary winding (34) of a high voltage pulse transformer (30). The low level current then passes through a shunt resistor (56) from ground to an input terminal of the source, thus completing the circuit and generating a voltage between the source input terminal and ground that confirms continuity of the circuit through the high voltage cable (40).

Very narrow band, two chamber, high rep rate gas discharge laser system

Laser excimer krf, a bande etroite, a qualite de production, modulaire et fiable

Line selected F2 two chamber laser system

A very narrow band two chamber high repetition rate F 2 gas discharge laser system comprising. A) a first laser unit comprising: 1) a first discharge chamber containing; a) a first laser gas b) a first pair of elongated spaced apart electrodes defining a first discharge region, 2) a first fan producing sufficient gas movement of said first laser gas in said first discharge region to clear from said first discharge region, following each gas discharge, substantially all discharge produced ions prior to a next gas discharge when operating at a repetition rate in the range of 4,000 gas discharges per second or greater, 3) a first heat exchanger system removing heat energy from said first laser gas, B) a line selection unit minimizing energy outside of a single selected line spectrum, C) a second laser unit comprising: 1) a second discharge chamber containing: a) a second laser gas, b) a second pair of elongated spaced apart electrodes defining a second discharge region 2) a second fan for producing sufficient gas movement of said second laser gas in said second discharge region to clear from said second discharge region, following each gas discharge, substantially all discharge produced ions prior to a next gas discharge when operating at a repetition rate in the range of 4,000 gas discharges per second or greater, 3) a second heat exchanger system removing heat energy from said second laser gas, D) a pulse power system configured to provide electrical pulses to said first pair of electrodes and to said second pair of electrodes sufficient to produce laser output pulses at rates of about 4,000 laser output pulses per second with precisely controlled laser output pulse energies in excess of about 5 mJ, E) a laser beam measurement and control system for measuring the laser output pulse energy of laser output pulses produced by said two chamber laser system and controlling said laser output pulses in a feedback control arrangement, and wherein output laser beams from said ...

Lithography laser with beam delivery and beam pointing control

The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source (Fig. 1) with a beam delivery to a production line machine (2). The system includes an enclosed (4) and purged beam path (14C) with a beam pointing control (40A) (40B) (6) for delivery of the laser beam to a desired location such as the entrance port of the production line machine (2). In preferred embodiments, the production line machine is a lithography machine (2) and two separate discharge chambers (8)(10) are provided, one of which is a part of a master oscillator (8) producing a very narrow band seed beam (14A), which is amplified in the second discharge chamber (10). This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality.

Regenerative ring resonator

Regenerative ring resonator

Gas discharge laser with improved beam path

Gas discharge ultraviolet wavemeter with enhanced illumination

The present invention provides a wavemeter for an ultraviolet laser capable of long life beam quality monitoring in a pulsed ultraviolet laser system at pulse rates greater that 2000 Hz at pulse energies at 5 mJ or greater. In a preferred embodiment an enhanced illumination configuration reduces per pulse illumination of an etalon by a factor of 28 compared to a popular prior art configuration. Optics are provided in this embodiment which reduce light entering the etalon to only that amount needed to illuminate a linear photo diode array positioned to measure interference patterns produced by the etalon. In this preferred embodiment tow sample beams produced by reflections from two surfaces of a beam splitter are diffused by a defractive diffuser and the output of the defractive diffuser is focused on tow separate secondary diffusers effectively combining both beams in two separate secondary diffusers effectively combining both beams in two separate spectrally equivalent diffuse beams. One beam is used for wavelength and bandwidth measurement and the other beam is used for calibration. In preferred embodiments an etalon chamber contains nitrogen with an oxygen concentration of between 1.6 and 2.4 percent.

Wavemeter for gas discharge laser

An optical configuration to illuminate an etalon (79) in a laser wavemeter (120) with a minimum level of light intensity. The system includes optical components to direct a portion of the laser output beam representing the entire cross section of the beam, through an etalon (79) positioned in an etalon housing, and onto a photodetector (180). A first lens (400) condenses the size of the beam sample, and a second lens (402) re-collimates the beam which then passes into the etalon housing, ensuring that all of the spatial components of the beam are adequately sampled. A diffractive diffusing element (406) is incorporated into the optical path. In a preferred embodiment, the diffractive diffusing element (406) is placed within the etalon housing. In another preferred embodiment, the diffusing element (406) is located up stream but outside the housing in the optical path.

Extendable electrode for gas discharge laser

Wavelength system for an excimer laser

F2-laser mit kontrolle des sichtbaren roten und ir-bereichs

Gas discharge laser line narrowing module

A line narrowed gas discharge laser system and method of operating same is disclosed which may comprise a dispersive center wavelength selective element; a beam expander comprising a plurality of refractive elements; a refractive element positioning mechanism positioning at least one of the refractive elements to modify an angle of incidence of a laser light beam on the dispersive center wavelength selection element; each of the dispersive center wavelength selection element and the beam expander being aligned with each other and with a housing containing at least the dispersive center wavelength selection element; a housing positioning mechanism positioning the housing with respect to an optical axis of the gas discharge laser system. The dispersive element may comprise a grating and the beam expander may comprise a plurality of prisms. The housing may contain the dispersive center wavelength selective element and the beam expander. The housing positioning element may comprise a position locking mechanism.

Four khz gas discharge laser system

Injection seeded f2 laser with wavelength control

Injection seeded f2 laser with line selection and discrimination

A narrow band F2 laser system having two laser subsystems. The first laser subsystem is a seed laser (100) and provides a very narrow band pulsed beam at a first narrow wavelength range corresponding to a first natural emission line of the F2 laser system. This beam is injected into the gain medium of the second laser subsystem (102) in a first direction where the beam is amplified to produce a narrow band pulsed output beam. The seed laser (100) also produces a second pulsed beam at a second wavelength range corresponding to a second natural emission line of the F2 laser. This line is injected into the gain medium of the second laser subsystem (102) in a second direction opposite said first direction. The second beam is amplified in the gain medium of the second laser subsystem of the second laser subsystem and depletes the gain medium of gain potential at the second wavelength range. Thus, the portion of light at the second wavelength range in the output beam (124) is greatly reduced.

Injection seeded f2 laser with line selection and discrimination

A narrow band F2 laser system having two laser subsystems. The first laser subsystem is a seed laser (100) and provides a very narrow band pulsed beam at a first narrow wavelength range corresponding to a first natural emission line of the F2 laser system. This beam is injected into the gain medium of the second laser subsystem (102) in a first direction where the beam is amplified to produce a narrow band pulsed output beam. The seed laser (100) also produces a second pulsed beam at a second wavelength range corresponding to a second natural emission line of the F2 laser. This line is injected into the gain medium of the second laser subsystem (102) in a second direction opposite said first direction. The second beam is amplified in the gain medium of the second laser subsystem of the second laser subsystem and depletes the gain medium of gain potential at the second wavelength range. Thus, the portion of light at the second wavelength range in the output beam (124) is greatly reduced.

Injection seeded laser with precise timing control

A narrow band laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed output beam which is used to injection seed the second laser subsystem where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply is provided which is specially configured to precisely time the discharges in the two laser subsystem so that the discharges are properly synchronized. Preferred embodiments include a pulse power system with a pulse transformer unit having two sets of transformer cores. A single upstream pulse compression circuit provides high voltage pulses in parallel to the primary windings of all of the cores in both sets. Separate secondary conductors (one passing through one set of cores and the other passing through the other set of cores) provide very high voltage pulses respectively to separate downstream circuits supplying discharge pulses to the electrodes in each of two separate laser chambers. Preferred embodiments include KrF, ArF and F2 systems. In these preferred embodiments, line narrowing may be accomplished within the resonant cavity of the seed laser or the output of the seed laser could be line narrowed using a pre-gain filter.

Injection seeded laser with precise timing control

A narrow band laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed output beam which is used to injection seed the second laser subsystem where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply is provided which is specially configured to precisely time the discharges in the two laser subsystem so that the discharges are properly synchronized. Preferred embodiments include a pulse power system with a pulse transformer unit having two sets of transformer cores. A single upstream pulse compression circuit provides high voltage pulses in parallel to the primary windings of all of the cores in both sets. Separate secondary conductors (one passing through one set of cores and the other passing through the other set of cores) provide very high voltage pulses respectively to separate downstream circuits supplying discharge pulses to the electrodes in each of two separate laser chambers. Preferred embodiments include KrF, ArF and F2 systems. In these preferred embodiments, line narrowing may be accomplished within the resonant cavity of the seed laser or the output of the seed laser could be line narrowed using a pre-gain filter.

Injection seeded f2 laser with wavelength control

The present invention provides a narrow band laser system having two laser subsystems. The first laser subsystem (seed laser) provides a very narrow band pulsed output beam which is used to injection seed the second laser subsystem (slave osc. or power amp.) where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply (pulse power) precisely times the discharges in the two laser subsystems so that the discharges are properly synchronized. The laser gas comprises F2 at a partial pressure less than about 1 % with a buffer gas comprised of helium, neon, or a combination thereof. Control of the center wavelength of the output beam is provided by adjusting one or more of the following parameters in the first laser subsystem: the total laser gas pressure, the relative concentration of helium or neon, F2 partial pressure, laser gas temperature, discharge voltage and pulse energy.

Injektionssynchronisierter laser mit präziser zeitsteuerung

ガス放電レーザに関するウェーブメータ

(57)【要約】 【課題】 ガス放電レーザに関するウェーブメータを提 供することを目的とする。 【解決手段】 レーザウェーブメータのエタロンを最小 レベルの光強度で照射するような光学的構成。系は、エ タロンハウジングに位置決めされたエタロンを介して、 フォトディテクタに、ビームの断面全体を表すレーザ出 力ビームの一部を差し向けるための光学コンポーネント を有する。第１のレンズはビームサンプルのサイズを縮 小し、第２のレンズはビームを再び平行化し、次いで、 ビームの空間的なコンポーネントの全てが適当にサンプ リングされることを保証するように、エタロンハウジン グ内に通す。回折散乱エレメントは、光パス内に組み込 まれる。好ましい実施形態では、回折散乱エレメント は、前記平凸レンズとエタロンとの間のエタロンハウジ ング内に配置される。

Hochleistungs-Seed-/Verstärkerlasersystem mit Strahlformung zwichen Seed und Verstärker

Bereitgestellt werden eine Vorrichtung und ein Verfahren zum Betreiben einer Hochleistungs-Breitband-Laserglühlichtquelle mit länglichem, dünnem Strahl, die enthalten kann: einen Gasentladungs-Seedlaser-Oszillator mit einem Resonanzhohlraum zur Bereitstellung eines Seedlaser-Ausgabepulses; einen Gasentladungsverstärkerlaser zum Verstärken des Seedlaser-Ausgabepulses zur Bereitstellung einer verstärkten Seedlaser-Pulsausgabe; eine divergenzkorrigierende optische Anordnung mit multioptischem Element zwischen dem Seedlaser und dem Verstärkerlaser. Die divergenzkorrigierende optische Anordnung kann die Größe und/oder Form des Seedlaser-Ausgabepulses innerhalb eines Entladungsbereiches des Verstärkerlasers anpassen, um einen Ausgabeparameter der Ausgabe des verstärkten Seedlaser-Pulses anzupassen. Die divergenzkorrigierende optische Anordnung kann ein Teleskop mit einem anpassbaren Fokus umfassen. Das anpassbare Teleskop kann einen aktivrückkopplungsgesteuerten Betätiger auf Grundlage eines erfassten Parameters der verstärkten Seedlaser-Ausgabe aus dem Verstärkerlaser umfassen.

能動的波長チャープ補正を用いる電気放電レーザ

(57)【要約】 【課題】 本発明は、レーザ放電レーザに関し、特に音 響外乱を補正する装置を持つレーザに関する。 【解決手段】 能動的チャープ補正を用いる電気放電レ ーザを提供する。本出願は、これら圧力波の緩和及び分 配に対する技法を開示する。レーザによっては、小さな 予期可能なパターンが残留し、それは、従来技術の比較 的遅速な波長制御装置を用いる能動的波長制御を使用し て、かなり補正することができる。好ましい実施形態に おいては、学習したチャープ・パターンを予期して予同 調ミラー調節ができるようにする単純な学習アルゴリズ ムが説明される。実施形態は、極めて精密な調節を持つ ステッパ・モータを含み、その結果、同調ステップの大 きさは、より正確な同調に対してかなり減少する。本出 願人は、超高速能動的チャープ補正に対する装置及び技 法を開発した。

Gas discharge laser line narrowing module

A line narrowed gas discharge laser system and method of operating same is disclosed which may comprise a dispersive center wavelength selective element; a beam expander comprising a plurality of refractive elements; a refractive element positioning mechanism positioning at least one of the refractive elements to modify an angle of incidence of a laser light beam on the dispersive center wavelength selection element; each of the dispersive center wavelength selection element and the beam expander being aligned with each other and with a housing containing at least the dispersive center wavelength selection element; a housing positioning mechanism positioning the housing with respect to an optical axis of the gas discharge laser system. The dispersive element may comprise a grating and the beam expander may comprise a plurality of prisms. The housing may contain the dispersive center wavelength selective element and the beam expander. The housing positioning element may comprise a position locking mechanism.