MOTION SENSOR INTEGRATED NANO-PROBE N/MEMS APPARATUS, METHOD AND APPLICATIONS

Cross-reference to related applications

This application relates to the filed 16 December 2011, name referred to as "nano-probe actuator (  Actuator   Probe Nano)" for the Serial numbers of the 61/576, 455 Patent of the United States Provisional application, and for priority of the application, the content of the application by reference and all the way into this application.

Government rights statement

Forming this application the embodiment and claimed in the present application of the invention in the study was conducted by the United States National science foundation, DMR based on a cooperation agreement   1120296 of financing. The Government of the United States for in the present application the claimed invention has an interest.

Technical Field

The present invention relates generally to micro-electro-mechanical system of nanometer size (N/MEMS) device and related method. More specifically, embodiments relate to integrated with a motion driving (actuation) and sensor (N/MEMS) nanometer scale micro-electro-mechanical system device and the associated method.

Background Art

Nano-based manufacturing process of the tip of the probe is often need to accurately place a plurality of nano-tip of the probe. Similarly, the tip of the probe is nano-based nano-measuring device can also be through the atomic force microscope (AFM) sensing method or scanning tunnel microscope (STM) sensing method to sense the surface of the entity to be contacted. Because the nano-manufacture process application and nanometrology device, which may continue to increase, the need of additional device for nano-based tip of the probe is, related method and the related application.

Content of the invention

An embodiment of the application includes having integrated JFET (junction field effect transistor) as a pre-amplifier, based on the tip of the probe is used for sensing a plurality of state-of-the-art nano probe device. Because the capacitive transducer is reduced to the nanometer scale, they therefore the impedance (1/jωC) greatly increased, this makes them vulnerable to parasitic capacitance, and RF noise derived from the local electrostatic field and RF coupling the impact of the charge of the electric field. The problem of the noise coupling, in the past the integrated scanning system to the work of the poor results, this is because of the need of the electronic device is connected to the chip of the connecting line of the coupling of the RF noise.

Therefore, an embodiment of the application to provide a compact integrated in the probe device of nanometer in the JFET, multiple tip Donald m probe device, is used to realize the local signal measurement, including a differential measurement. The JFET device is monolithically integrated on the device N/MEMS, in order to reduce parasitic circuit element, signal and the impact of the mismatch. JFET is also directed to a low noise operation is provided with an on-chip gain and impedance transformation. Because the JFET low 1/f noise, high-gain, in the manufacture of the mask quantity is less, there is no parasitic diodes, and is not sensitive to electrostatic discharge, is used for the JFET N/MEMS signal conduction ideal candidate.

In some embodiments, its position may be with respect to the substrate the nanometer the tip of the probe is free to move (i.e., nanometer the tip of the probe is not attached to the substrate) through electrostatic energy maintains the interval (  gap electrostatic   energy   sustaining) mate to the JFET electrode, and can be two ways of sensing JFET. 1st, in the channel of the JFET in electrostatic force caused by the strain, the strain tends to change the carrier mobility of the channel of the JFET. 2nd, nanometer of the device of the probe on the probe arm of charge in the coupling of a gate electrode of the JFET produce the floating potential, the floating potential channel current of the transistor can be modulated into the signal to be measured.

In some embodiments, the nano-probe can move freely through the zigzag spring (meander   spring) are received and JFET electrode, thus the nanometer can be freely moved relative to the tip of the probe is the purposes of position and movement, the spring twists and turns together with the JFET can be seen as a motion sensor.

As noted above, in some embodiments, "freely movable" means the absence nano the tip of the probe is attached to the tip of the probe of the substrate.

In some embodiments and in the claims, the use of two layers on the substrate or "above" the terminology of the structure used to represent the two layer or two structural overlapping space and layout, however, two layer or two structures do not necessarily contact. On the contrary, on the substrate of the above two layer or two structural terms "top" refer to the two layer or two structural overlapping space and layout, and the two layers or contact structure.

In some embodiments and in the claims, is to be hoped that all layers and structure are located in and are formed in a single substrate.

In some embodiments and in the claims, use about movement of the part of the sensor, the term "coupled with" or "is operably coupled to", or can be moved on the motion sensor is coupled to a probe tip, is of beacon , mechanical, electromechanical or other type of connection, the connection of the and provide the necessary signal results of the mode of operation.

In some embodiments and in the claims, the terminology of the motion sensor on the "pressure-sensitive part" also implies that included in the unit area of the sensitive components under the condition of, its operation therefore usually derived from the operation of the pressure sensitivity.

In some embodiments and in the claims, on at least one movable probe tip and at least one of the tip of the probe is "pointing in the same direction" means the direction of the nominally the same, and is taken into consideration to a set of the movable and can move the tip of the probe in the tip of the probe of any one of the offset of the peak relative to the other tip.

According to these embodiments the specific nano probe device includes a substrate. This specific nano probe apparatus also includes a is located on the substrate of the at least one movable probe tip. The at least one movable probe tip can move with respect to the substrate. This specific nano probe apparatus also includes a is located on the substrate of the at least one motion sensor. The at least one movement sensor includes with the at least one spring operable the pair meets at least one of the pressure-sensitive part. The at least one motion sensor with the at least one movable probe tip is operably coupled to.

According to the embodiment of the another specific nano probe device includes a substrate. This in addition to the specific nano probe apparatus also includes a is located on the substrate above the at least one of the tip of the probe is not movable. The at least one movable probe tip can not move with respect to the substrate. This additional nano probe apparatus also includes a is located on the substrate of the at least one movable probe tip. The at least one movable probe tip can move with respect to the substrate.

According to these embodiments a specific nanometer probe device includes a substrate. This in addition to the specific nano probe apparatus also includes a is located on the substrate above the at least one of the tip of the probe is not movable. The at least one movable probe tip can not move with respect to the substrate. This additional nano probe apparatus also includes a is located on the substrate of the at least one movable probe tip. The at least one movable the tip of the probe relative to the substrate and can be movable relative to the tip of the probe is not mobile. This specific nano probe device also includes a substrate of the above, and with the at least one movable probe tip coupled at least one motion sensor.

According to these embodiments the specific detection method includes placing a probe relative to the sample in the device can be at least one of moving the tip of the probe, said probe device including : (1) a substrate ; (2) is located on the substrate of the at least one movable probe tip, the at least one movable probe tip can move with respect to the substrate; and (3) is located on the substrate of the at least one motion sensor, said at least one motion sensor includes at least one pressure sensitive component and at least one spring, said at least one motion sensor and at least one movable probe tip is operably coupled to. This particular detection method also includes the measurement of said at least one motion sensor at the same time of the output signal, so that the at least one movable probe tip relative to the sample mobile.

According to these embodiments of the method for detecting a specific sample placing probe device includes at least one of the plurality of moving the tip of the probe, said probe device including : (1) a substrate ; (2) is located on the substrate above the at least one of the tip of the probe is not removable, the at least one movable probe tip can not move with respect to the substrate ; (3) is located on the substrate of the at least one movable probe tip, the at least one movable probe tip can move with respect to the substrate; and (4) is located on the substrate of the at least one motion sensor, with the at least one movable probe tip is operably coupled to. This in addition to the specific the method also includes measuring the at least one motion sensor at the same time of the output signal, so that the at least one movable probe tip relative to the sample mobile.

Description of drawings

The purpose of the embodiment of, features and advantages can be in the following specific embodiment in the content of understanding. Specific embodiments, the content of the picture, Figure constitutes an important part of the present disclosure, wherein:

Figure 1 of the embodiment of the display in accordance with the probe, JFET, and the restrictor ; (S) of nanometer more tips plan view of the device of the probe, the actuator stop limits F3 the movement of the comb-shaped part of the outside of the;

Chart 2 display : (A) of the JFET with tortuous SEM micrograph of the spring; and (B) in accordance with the present invention a plurality of nano-tip side view of the device of the probe are SEM micrograph;

Fig. 3 display according to an embodiment of the state-of-the-art nano probe device in piezoelectric strain of the channel of the JFET driving and sensing a schematic diagram, fig. 3 also shows the doping profile of the JFET;

Fig. 4 display according to an embodiment of the state-of-the-art nano probe device in JFET twists and turns of the spring and the tip of the probe (k2) simulation COMSOL of displacement, the tip of the probe along the x and y shaft can be mobile;

Figure 5 show Figure 4 COMSOL model of the simulation result, in the F3 is 18 volts in the driving voltage can be generated at the tip of the probe 120 nm displacement, generated at the transistor twists and turns 15.5 nm displacement. The tip of the probe; and can move in the opposite direction;

Fig. 6 displayed in the F3 is applied, a scanning voltage ramp, ac caused by a movement of the electric current is the displacement of the movable with the tip of the probe is F3 measuring between;

Figure 7 shows the measurement of the JFET I_DS relative to V_DS output curve, V_gate2 is floating, and V_gate1 with V_G1 changes;

Figure 8 display in V_DS = 10V under the bias of, according to an embodiment of the transfer curve of the JFET, wherein I_on/I_off ratio is 126;

Figure 9 shows the application of the driving voltage with the tip of the probe is the movement of the JFET transistor, the JFET can be capable of sensing the movement of the tip of the probe is, in the floating potential induced on JFET and strain modulation the drain current, for these experiment, V_gate1 is set up in the 0 volt;

Figure 10 shows the movable with the tip of the probe is measured between tungsten sample the contact current is low, it may be because the movable is formed at the tip of the probe can be oxide or because of the high tip of the probe is in series electrical resistance;

Fig. 11 display when using the fixed ion beam from the ion gun at the time of cutting the sample, the tip of the probe relative to the position of the sample is of the ion gun 52 degrees;

Figure 12 of the tip of the probe before cutting FIB, wherein the top layer is MoSi₂;

Figure 13 the display is exposed to the ion beam with MoSi₂ cutting FIB of the tip of the probe;

Figure 14 displayed on the is exposed to the ion beam with MoSi₂ FIB of after cutting of the tip of the probe, a side view of the tip of the probe can be moved, wherein the MoSi₂ tip of the tunnel forming the device.

Figure 15 the rear movable FIB cutting a side view of the tip of the probe, wherein MoSi₂ by 300 nm of SiO2 protection;

Figure 16 for display according to an embodiment of the multi-state-of-the-art nanometer probe device for moving the tip of the probe of the measurement resonant frequency of the electric device;

Figure 17 display in 1.9e -3mbar pressure vacuum, under which the movable probe tip of the resonant frequency measurement result;

Figure 18 on the display PCB board, according to an embodiment of the assembled probe NEMS, the PCB board is finally installed on JEOL in   SPM system, HOPG N/MEMS sample is placed in the lower part of the probe;

Figure 19 display (A) sold on the market of the scanning tip Pt-Ir HOPG sample; and (B) according to an embodiment of the probe scanning N/MEMS HOPG sample;

Figure 20 display (A) is installed in the probe and in the SEM sample HOPG N/MEMS, HOPG for in-situ analysis of the conductance of the sample; and (B) SEM using Zyvex nano positioner in a schematic diagram of the test assembly;

Figure 21 display according to an embodiment of the probe tip of the probe N/MEMS HOPG sample soft contact (  contact soft) of the SEM micrograph;

Fig. 22 according to the embodiment of the display through the use of multi-state-of-the-art nanometer probe device to measure conductance characteristics of the sample of the HOPG, dashed-line is movable linear fitting of the tip of the probe current, and the resistance of the HOPG sample by this determining the reciprocal of the slope of the straight line;

Figure 23 embodiment of display on the basis of the state-of-the-art nanometer probe device : (A) all of the state-of-the-art is grounded ; (B) + 3.5V is applied to the tip 1 ; (C) + 3.5V is applied to the tip 2;

Figure 24A to 24T display a set of illustrative a perspective view, according to the showing of the embodiment of the manufacturing, integrated with a motion sensor N/MEMS a plurality of nanometer probe tip device is the result of gradual processing stage;

Figure 24A display is used for manufacturing according to embodiments of the SOI substrate of the device of the probe, the surface is silicon device layer 2 the thick   m, buried oxide layer has a thickness in the range of the 1-2  m;

Figure 24B display SiO₂ layer and a chromium (Cr) are sequentially deposited on the chart 24A above the SOI structure, for chrome as used for SiO₂ etching mask film;

Figure 24C display spin-coating the photoresist layer, and using (DUV) lithography to patterning deep ultraviolet source and drain of the JFET extreme;

Figure 24D display source and drain extreme pattern is reactive ion etching (RIE) to form Cr and SiO₂ mask film;

Figure 24E is removed and display Cr SiO₂ is used as a diffusion mask, PH-1025 solid source target (solid   target   source) is used for the phosphorus dopant diffusion to source and drain, and is annealed in order to drive in the dopant;

Figure 24F display through the use of hydrofluoric acid to remove (HF) SiO₂ diffusion mask;

Figure 24G display repeat step 24B to 24D, but at this time, source, drain and for the channel region SiO₂ protection;

Figure 24H display BN-1025 solid source target sundries the boron mixes is used for the JFET gate region and the comb drive, the drive electrode and a tip region;

Figure 24I display through the use of hydrofluoric acid (HF) removing SiO₂ diffusion mask;

Figure 24J of display sputtering deposition covers MoSi₂ layer, and the covering MoSi₂ the top of the layer of spin-on photoresist;

Figure 24K display channel region and be patterned is etched by the RIE MoSi₂, at this moment, only channel JFET N-type silicon;

Figure 24L display the oxygen plasma stripping of the photoresist, SiO₂ and Cr mask is deposited;

Figure 24M display of spin-on negative photoresist, and using the DUV lithography to pattern Warner m probe device;

Figure 24N display Cr, SiO2 and MoSi₂ stack is RIE etching downwards, until the silicon device layer;

Figure 24O displayed before the etching of the silicon device layer, respectively for 1165 solvent and removing photoresist and etching agent Cr Cr layer, SiO₂ mask is used for deep reaction ion etching (DRIE) silicon device layer;

Figure 24P display to expose the tip, turning the wafer, deposition SiO₂ and spin-coating photoresist. Back SiO₂ and is patterned RIE etching;

Figure 24Q display is used as the back surface of the etching mask SiO₂, for sculpture handle shape wafer, the oxide layer until the buried layer;

Figure 24R display the MoSi₂ before annealing, the RIE etching device layer SiO₂ etching mask film;

Figure 24S display focused ion beam is used to enable the tip is tapered;

Figure 24T HF display the device to release the gas.

Mode of execution

Embodiment provides more tips and nano probe device for operating the above-mentioned state-of-the-art method for nanometer of the device of the probe. Because the motion sensor and the movable probe tip closely coupled to the multi-tip nanometer probe device, multiple tip Donald m probe device and the associated method provides improved performance. Furthermore, because the movable tip of the probe tip relative to the plurality of nano-probe device can be the mobile probe tip is operable, therefore multiple tip nanometer probe device and the associated method provides improved performance and improved capacity. Movable and the tip of the probe can be the tip of the probe to move together with nanometer-scale, the nanometer level to the measured property of the space distance is important.

1. General considerations

According to an embodiment of the state-of-the-art nano probe device comprises a substrate (i.e., preferably a single substrate), the included in the 1st example, and is formed in the substrate located in the upper part of at least one of (and preferably at least two, or more than two) can move the tip of the probe and at least one motion sensor. According to an embodiment of the state-of-the-art nanometer probe device also includes and is formed in the substrate at least one of the above mobile the tip of the probe, the at least one motion sensor is operably coupled to. In an embodiment, the at least one movable probe tip usually relative to the at least one can not move the tip of the probe is retractable, and through the at least one driver can be operationally connected to at least one motion sensor.

Although some example is in the nanometer more tips of the device of the probe described in the background, wherein the multiple tip Donald m through the probe device includes signal transducer for movement of the twists and turns the spring by the purpose of electrostatic and mechanically is coupled to the device channel of the JFET can be mobile state-of-the-art, however, these embodiments also can be expected, and at least one spring of the other pressure-sensitive member (such as the piezo-electric-sensitive circuit component) and also can be used for the purpose can be motion signal. Such other pressure sensitive part can include, but are not limited to, the piezoresistive and piezoelectric transducer, it gathers together referred to as piezoelectric transducer, according to the embodiment for the multi-tip nano probe device the movement of the part of the signal transducer, replace the JFET channel. These other piezoelectric transducer component can include, but is not necessarily limited to, piezoelectric crystal piezoelectric transducer or part and piezo-resistive component. Therefore, according to an embodiment of the motion sensor can include multiple physical motion sensor, which includes the integrated transistor amplifying photosensitive resistor or capacitor, but also can be measured through the current mobile the tip of the probe.

Similarly, although the example is in the nanometer more tips of the device of the probe described in the background, wherein the multi-state-of-the-art nanometer probe device comprises two relative to the substrate and the motion sensor can not move the tip of the probe, and movement of one with respect to the substrate and moving the tip of the probe sensor can be used, but the embodiments are also not intended to be limited to this. But, embodiment it is expected that includes at least one with respect to the substrate and of the motion sensor and at least one tip of the probe relative to the substrate and the movement sensor can be of a plurality of the tip of the probe tip nano probe device.

In an embodiment, for the at least one movable probe tip and the at least one movable probe tip, with each of them from about 30 to about 500 micron length and from about 300 to about 1000 nano the transverse dimension (i.e., diameter), and also suspended above the substrate. Furthermore, each of the at least one movable probe tip with each of the at least one movable probe tip spaced from each other from about 100 to about 1200 nanometers of distance.

In an embodiment, by properly selecting the number of the of the integrated actuator and the tip of the probe, the probe tip may be movable relative to the substrate or at least one can not move as the tip of the probe is of oval 3D track movement. Furthermore, in the implementation of the transmissions, can not move the tip of the probe can be the tip of the probe and can move in accordance with the discussion further below to the atomic scale is sharp, with a radius of curvature of less than about 1 nanometer.

2. Operating principles

Multi-nanometer probe the operation of the system can be adopted to aid in the JFET, may be used, however, the operation of the JFET transistor. According to an embodiment of the state-of-the-art nano probe device in the operation of the JFET, however is generally conventional. Embodiments thus now demonstration and described in the JFET according to the embodiment of the multi-state-of-the-art nanometer probe device for use in. According to an example embodiment, the above-mentioned differential state-of-the-art structure is composed of a movable probe tip (tip 3) and two stationary can not move the probe tip (tip 1 and tip 2) is made, as shown in Figure 1 and Figure 2. Movable probe tip may be actuator through the use of static plate F1 and F2 along the y shaft drive. The voltage applied to the tip 1 and tip 2, also can make the movable tip 3 lateral offset. Can be through the use of in the F3 and the tip 3 to the electrostatic force between the mobile can be moved along the X direction of the tip of the probe. JFET (J1) is suspended from, and through the zigzag spring capacitively and the mechanical operatively coupled to actuator F3.

The JFET channel is lightly n-type doped (3.11x10^-15 cm^-3), grid p+-type doping (10²⁰ cm^-3), is a source electrode and a drain electrode-type doping n+ (10²⁰ cm^-3). Figure 3 is a schematic diagram of JFET, the JFET shown not only the same, is also shown connected to a gate electrode of the electrostatic actuator of the twists and turns of the spring F3 connection.

A. JFET current from floating potential contribution to the

Sensing of the JFET through the reverse biasing the grid part I 1 and is biased to saturation. Saturation current is:

ID=IDSS(1-VGSVP)2---(1)

Wherein I_DSS is when the V_GS = 0 the saturation current of the the, and V_p off-voltage is used for. When the negative DC voltage is applied to the F3, , JFET extending bent portions, while at the same time the probe to the X direction. Because the JFET twists and turns of the spring is electrically floating, therefore in the F3 the voltage applied on the spring the tortuous generating negative floating potential.

The potential reverse bias JFET gate 2, is used to further pinch-off channel. The floating potential will modulate the channel conductance, in the JFET the new saturation current can be written as:

IDD=IDSS(1-(VGS+ΔVFG)VP)2=IDSS(1-VGSVP)2[1-ΔVFGVP-VGS]2---(2)

IDD=ID[1-ΔVFGVP-VGS]2---(3)

Wherein Δ V_FG is floating potential. If V_P-V_GS > Δ V_FG, when the floating potential to reduce the leakage current will increase.

B. The current contribution from the strain

When the voltage is applied to the F3, , stretching of the grid and extending of the spring, and between the channel and the twists and turns of the spring produce strain p+n-junction. In the strain of the depletion region in the channel of the JFET tensile stress is generated. The effect of the tensile stress is to enhance the channel mobility. When in saturation, the drain current is:

ID=IDSS(1-VGSVP)2---(4)

IDSS=μn(qNd)2tW36εoεsiL{1-3(VbiVPO)(1-23VbtVPO)}---(5)

Wherein W is the width, the thickness of the JFET t is, and that the length L. If mobility Δμ representative small change, the new current is:

IDD′=ID[1+Δμμ]---(7)

According to equation 7, increased mobility in the change of the electric current of the drain of the JFET. This and increased floating potential effect on the contrary, the latter attempt to cut-off channel and reduce the current. In this device, floating potential is the dominant effect.

C. As the measurement of the capacitance of the sensor

As shown in Figure 1 the comb-like electrode C1 and C2 can be measuring includes moving the tip of the probe is the relative position of the mobile arm. When moving on the arm, the mobile arm and C1 and C2 of the two comb-like electrode of the capacitance value between the fixed comb means will change.

D. Electro-mechanical driving simulation

Because the JFET can be moved in response to the movement of the tip of the probe, the change of the drain current can be used for characterization of the movement. Figure 4 shows the structure of the device simulation COMSOL and electrostatic behavior.

The twists and turns is connected to JFET effective elastic constant of the spring (2k1 + k2) is designed to be connected to the movable than the those of the tip of the probe (2k1) more hard. Fig. 5 shows when the voltage is applied to the F3 can be moved in the direction of the tip of the probe and twists JFET x spring (k2) the relationship between. Limiter is used to prevent the drawing-in period and the tip of the probe can be moved over the limit of the JFET. Movable than the tip of the probe tip of the probe is not removable long 100 nm. The electrode driver F3 the voltage is applied, and the tip of the probe can be moved along the tortuous JFET to move in the direction opposite of the spring. With the tip of the probe can be moved from the default position to the 500 nanometer range of movement, this makes the movable relative to the movable tip of the probe is the tip of the probe is retractable or extendable.

3. Fabrication of the device

According to an embodiment of the multiple tip nano probe device is manufactured with the   et   al. Amponsah, "Monolithically   integrated   NEMS   FETS   and   junction,"   Mechanical   Electro Micro   Systems (MEMS), 2011IEEE   24th   International   Conference   Proceedings, pp. 91-94, 23-27   Jan. 2011 method described in parallel, the paper in order to can allow all the extent of the way by a reference in the present application. The device of the device and associated electrical resistivity as the use 2ohm-cm, 2 the thick   m n-type SOI wafer manufacturing. Through the use of a source electrode and a drain electrode PH-1025 solid source doping proliferates the target , and the grid BN-1250 for solid source doping proliferates the target. Doped wafer in the furnace anneal in order to driving the dopant. MoSi₂ is used for metallization, and the device through the DRIE etching. Device and associated release of the device is in a gaseous state (HF) in hydrofluoric acid. By the design and selection mask version group , in order to offer such as in fig. 3 (b) display on a particular device.

In Figure 24A to Figure 24T is a perspective view of a group of specific, used for making the same according to the embodiment of the multi-state-of-the-art of nanometer order of the device of the probe. Each picture in a specific explanation is given above in the Figure.

4. Operation results and discussion

A. Movable electrostatic driving the tip of the probe

The F3 driver electrode applying a ramp voltage (ramp   voltage) can be confirmed that the movement of the mobile the tip of the probe. Figure 6 shown in the F3 and the tip 3 the displacement of the measuring current. Applying different peak voltage of the ramp voltage (Figure 6 on shaft x) and 0.8V/sec under the condition of the ramp rate, can be measured because the movable tip of the probe displacement current caused by movement. This displacement current can be used to independently measure the movement of the movable tip of the probe, in order to calibrate the transducer JFET.

The IV characteristic b.JFET

IV measurement is of the JFET device in the air by using the Keithley   4200 of the parameter analyzer. Figure 7 shows the drain of the JFET device with respect to the drain voltage voltage of the electric current. Transconductance and transconductance parameter measured respectively (β) is the 0.2 and   S 4.1nA/V². Table 1 parameter of the device is shown.

Table 1: the device parameter

By the equation 8 given pinch-off voltage measurement in V_DS = 10V is -25V, as shown in Figure 8.

V_p = V_pi-V_po     (8)

Vpo=qW2Nd2εoεsi---(9)

According to equation 8 and equation 9 can be seen, clip off-voltage JFET device is proportional to the doping concentration. Lightly doped channel to reduce the JFET pinch-off voltage of the device, this will reduce the drive current of the JFET device and transconductance. In the off-voltage current characteristic for a compromise between the high operation voltage for the operation of the electrostatic driving of the design problem of optimization.

C. JFET sensing can be moved by the movement of the tip of the probe

In order to detect the movement of the movable tip of the probe, the negative voltage applied to the different F3 is, monitoring the drain current modulation, is as shown in Figure 9 shown in the output curve.

Strain caused by an applied voltage, and will be reflected to the floating potential on JFET, the floating potential channel conductance modulation to a high level. For V_F3 =-20V, compared with V_F3 = 0V change of electric current the 0.4  A, this means that the JFET device grid 2 is the effective potential -2.3V.

D. The tip of the probe/contact of the tunnel current measurement

According to an embodiment of the state-of-the-art nano probe device can be applied to a field including but not limited to, scanning probe microscopy, biological nano-detection, the nanometer strain applied to the film material and the implementation of nano-conductance measurement. In order to measure the contact current, the Si tungsten sample contact with the tip of the probe. The measured contact current is low (in the sample to the tip voltage as 20V to 100fA), the typical nA STM current is in the range of levels.

The observed low current may be due to the Si in the nanometer of the device of the probe is formed at the tip or tungsten sample oxide. Furthermore, the nano-scale size of a nano-probe, series resistance is likely to have an impact on the electric current that is measured. For this purpose, and as discussed below, will MoSi₂ metal layer is introduced into the multiple tip Donald m the top end of the feeler arms, in order to reduce the series resistance. Figure 10 shown with not MoSi₂ measuring contact current.

E. The material and dimensions of the tip of the probe

As mentioned above, nanometer more tips in order to reduce the series resistance of the probe, the probe tip could be considered the top silicon MoSi₂ metal. MoSi₂ is annealed (in Ar/H₂ in the 750 the under [...] 3 minutes), thus form a firm interface with the tip of the probe of the electric contact and physical contact. If there are no such annealing processing step, the BOE or gas release HF, MoSi₂ will be due to a stress gradient stripped from the tip of the probe. To replace the Si is used for the surface scanning, MoSi₂ will be used for scanning the surface of the metal.

Traditional metal STM Pt/Ir the tip is made of tungsten or normally. In order to by the tungsten wire to form the atomic-scale sharp tip, using an electrochemical process to etching the tungsten wire metal. During the chemical etching, the metal-solution of the junction surface, and the metal part of the immersed in the etchant in dissolving away from the line, and this thread form the atomic-scale tip. In the case of line Pt/Ir, can be using the pliers to apply strain, in order to cut the Pt/Ir line.

These technology for nano probe is not ideal. Can consider needless to electrochemical etching or strain application and form, it has to be less than 50 nm metal STM the diameter of the tip of the tip of the new method. The focused ion beam of the indium is used for (FIB) to 52 degrees of angle cutting tip of the probe. Fig. 11 display JFET device and device with respect to a mounting orientation of the ion beam.

In the ion during grinding, the sharpened tip of the probe of the ion gun. Figure 12 is SEM picture of the situation before cutting of FIB, Figure 13 and Figure 14 is the probe after cutting FIB like. It should be note, this sharpening the tip of the probe is the only MoSi₂ layer of material is exposed to the ion beam only occurs.

By manufacturing including useful 300 nm   SiO₂ protection MoSi₂ layer of the focused ion beam device, the above-mentioned observation result can be confirmed. Point to 52 degrees is cut. Figure 15 shown 52 degrees SEMa side view of cutting. As can be seen, the tip of the probe is consistently used SiO₂ protection, the tip of which has a greater diameter. The use of the voltage FIB beam 0.28nA is the ion beam current 30KeV. Although the shown device reach 52 degree angle, but it is understandable, gallium ion beam through the choice of the angle between the with the probe arm, other angle, specifically at about 30 degrees to about 60 degrees of ranges, is also feasible.

5. Application example

A. The resonant frequency measurement

The JFET device according to an embodiment of the multi-state-of-the-art nano probe device can be used for AFM and STM application. In these applications, the movable probe tip may be excited into resonance, and along the surface of the sample scanning. As shown in Figure 16 by using the same device as the device for, moving the tip of the probe is in the resonance frequency can be of 1.9   e-3 measured in the vacuum   mbar.

SOI substrate is ground, and by using the lock-in amplifier   Instruments from Zurich (HF2LI), through the bias power supply, through the bias power supply scanning AC DC voltage combined with (bias-tee), and the electrode F3 starting. Through the displacement of the movable tip of the probe current is supplied to the sensitivity is set to 5nA/V low noise transimpedance amplifier (TIA). TIA output is fed to a lock-in amplifier, used for frequency domain analysis. Figure 17 shows the measured mobile the tip of the probe of the fundamental resonant frequency.

Moving the tip of the probe is measured as the resonant frequency of the 239.7KHz, as shown in Figure 17. Figure 17 in the illustration is the result of optical measurement of resonant frequency, its is 291.5KHz. Moving the tip of the probe is of elastic constants 5.54N/m, this shows that the precise placement and the contact but have pressing can be used to move the tip of the probe is of sufficient rigidity. Brown noise displacement through the use of equation 10 is evaluated.

x[!OverBar!]=4kBTbk2{1[1-(ωωo)2]2+ω2(Qωo)2}m/Hz---(10)

Wherein k_B is constant potts is graceful (1.38066x10^-23 J/K), T that the temperature (300K), b is the attenuation coefficient (0.37x10^-6 N   s/m), k is an elastic constant (5.54N/m), ω₀ is the resonant frequency of the measured (1.5x10⁶ rad/s), and Q is quality factor (-10). When in resonance, expected to be brown noise strength 78x10^-15 N/sqrt (Hz), displacement is the average noise 0.14x10^-12 N/sqrt (Hz). The displacement of the noise on the tip rather than provide sufficient for the transverse measurement of the majority of the SNR 2D thin film of low atomic distance between two orders of magnitude.

B. High-order pyrolytic graphite (HOPG) scanning tunnel microscope

In order to study the HOPG atomic arrangement, the manufacture with two static state-of-the-art multi-tip nano probe device. By moving the tip of the probe can be sharpened FIB, and is wire-bonded to the PCB board, as shown in Figure 18. PCB plate is inserted together with the probe NEMS JEOL   4210 in   SPM system. The tip of the probe can be moved through the ground and will be applied on the sample HOPG 350mV, the sample is placed in close proximity to the position of the probe tip can be moved, until the sensing to 500 Pa until the current, and then starting the ambient air 5nmx5nm the sample scanning. Figure 19A and 19B commercial Pt/Ir is shown separately and according to an embodiment of the scanning results of probe N/MEMS obtained.

C. Conductance measurement

According to an embodiment of the probe and N/MEMS HOPG the sample is mounted on the SEM manipulator (manipulator), as shown in Figure 20. In the SEM to observe in real time the movement of the probe towards the sample direction, in order to avoid excessive of the probe into the sample in advance, this will likely break state-of-the-art. Once the soft contact (  contact soft), voltage ramp is applied to the movable tip of the probe, and state-of-the-art recording current from the side, this provides a different conductance measurement results.

Figure 21 and Figure 22 showing the soft contact of the sample, respectively, and a current-voltage characteristic. The movable tip of the probe is not removable with the right between the resistance of the tip of the probe is accurately 0.4     / nm². It was also observed that, during the hard contact, when the movable tip of the probe is retracted, the outermost two can not move the tip of the probe can be bent 30 degrees without rupture.

D. The peak interval modulation

The ramp voltage can be applied by any one of the electrodes F1 or F2 can be reduced by moving the tip of the probe with any mobile one interval the gap between the tip of the probe. Furthermore, the voltage applied to the tip 1 and the tip 2 can be laterally offset can move the tip of the probe. Figure 23 shows the moving probe tip can be on-site of the SEM Image, the movable tip of the probe is at the middle of the ground, and can not move to the side of the tip of the probe is coupled with voltage. By modulating the spacing, can study delivery phenomena, such as local, and ballistic transport of the proliferation of the transfer.

6. Multi-tip nanometer probe device for a SUMMARY of the mode of operation

According to the embodiment are listed below the multi-tip nano of the device of the probe to the operating characteristics of the various applications.

I.STM mode

A. In the middle between the plus voltage of the thin film.

B. Sensing the electric current of the tunnel.

C. Scanning thin film, in order to research atomic arrangement and other characteristics.

II.AFM mode

A. Through the combined AC and DC voltage is applied to the electrode F3 is, excitation intermediate tip resonance.

B. Tracking the change of the state-of-the-art the vibration amplitude.

The scanner c.PZT z signal is used to reflect atoms of the film.

III. A transconductance mode

A. The intermediate tip retracted.

B. The tip is placed in close proximity to the outside of or completely contact thin film.

C. In the most outside to between the tips of the current-voltage measurement.

IV. B transconductance mode

A. The intermediate tip retracted.

B. Close to the tip of the outermost or completely contact thin film.

C. Intermediate state-of-the-art is now placed into abutting or contact thin film.

D. State-of-the-art and the most outside in the middle between the tips of the current-voltage measurement carried out. (Through the outermost electrode driving current, in order to produce the voltage of across the film. The inner electrode is used for measuring the voltage of the high input impedance. In this kind of method, the contact resistance of the electrode does not affect the thin film resistivity. )

V. Tunnel gap modulation

A. The intermediate tip retracted.

B. The outermost tip is used for the probe alignment film.

C. Intermediate state-of-the-art as gate, and the outermost tip as a source and a drain.

D. The ramp voltage is applied to the F3, the tunnel gap can be changed (in the middle tip of the gap between the sample).

E. The tip is applied to the middle of the voltage on the drain terminal can be modulated between the source of the channel conductance.

VI. Applied strain

A. Intermediate state-of-the-art can be used for the thin film applied strain.

B. The tip can be in the middle with the outside at the same time between the tips of the current-voltage measurement.

VII. The peak interval modulation

A. The ramp voltage is applied to the F1 and F2 will change on the outside of the tip of the middle of the interval between the.

B. The ramp voltage will also be applied to the outermost tip of the tip of the middle of the transverse offset, so as to change the peak interval.

VIII. Local scanning

A. The intermediate tip is placed in close proximity to the position of the sample.

B. The ramp voltage is applied to the F1 and F2 upper, intermediate state-of-the-art can be used for partial scan the area between the outermost tip.

7. Conclusions

Active JFET, electrostatic sensor and actuator is integrated to the has two can not move the tip of the probe and 3rd tip of the probe can move three the tip of the probe of the scanning probe tip device and device. When the movable to move the tip of the probe, of the JFET to reverse bias the JFET further floating potential. Depletion of change of the width of the JFET channel conductance, this makes it possible to directly pre-amplifying the movement of the movable tip of the probe. Furthermore, stretching of the spring caused by twists and turns twists and turns of the spring coupled to produce strain in channel JFET. Strain and floating potential effect of the role of the counter, but floating potential of the device is the main mechanism and related devices.

All the reference information, including the applications referenced publications, patents and Patent applications, in order to allow all the extent of the way by reference into this application, as each of the reference information is individually and in particular on the manner of the incorporated into this application by reference and set forth in the present application as in all.

In the described context of this invention, the term "a" and "an" and "the" and the use of similar pointer word (especially in the right context of the request) is understood as covering the singular form and most of the forms, unless in the present application indicated in clear contradiction or with the context. The term "including", "having" and "comprising" should be read as open-ended terms (i.e., mean "including, but not limited to"), unless otherwise noted. The term "be connected" should be understood as partially or completely included, is connected to, or combined together, even if some things in the middle of the range.

In the present application only in the desired range of values for an enumeration of the as a separate application within the range of each single value of the shortcut method, unless the indicated herein, and each single value is as its independently referenced herein in the specification as comprising.

All methods described herein can be performed in any appropriate order, unless indicated in this text or in other ways clear contradiction with the context. The use of any or all of the example, provided herein, or exemplary language (e.g., "such as") use, only expect better illustrate the embodiment of the invention, but not to restrict the scope of this invention, unless otherwise stated.

The language in the specification should not be seen as the requirements of any non-rights is specified as for the implementation of the invention is necessary.

The technicians of this field can be understood the embodiment herein can make various modifications and changes, without departing from the spirit and scope of this invention. This application is not desired will implement example or this invention limited to the specific form disclosed, but on the contrary, the desired covering as defined in claim the programme all corrections, replacement programme and equivalent structure. Therefore, this embodiment and invention covers the desired programme and modifications of the present invention changes, as long as they belong to the same requirements and their enclosed within the range of the programme.