Methods and techniques for determining when probe tip approaches or contacts sample surface

Abstract

Micron and nanoscale probes are used in the semiconductor and thin film material industry to test wafers and samples. The probe supplies a signal to the sample and measures a signal from the sample. The signal may be an electrical signal, a mechanical signal, a chemical signal, an optical signal, or a photonic signal. Techniques for capacitive response signals, intensity response signals, photocurrent response signals, piezoresistive response signals, high frequency response signals, elongation image response signals, contrast response signals, electrical response signals, resonance response signals, current response signals, and / or in-plane current response signals may be used to determine when a probe tip approaches or contacts a sample surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 482,489, entitled “Methods and Techniques for Determining When a Probe Tip is Proximate to or in Contact with a Sample Surface,” filed on January 31, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to methods and techniques for determining when a probe tip is near or in contact with a sample surface. The probe tip is used to test semiconductor and thin film materials. Background Art

[0004] As semiconductor device sizes continue to shrink, the electrical performance of these devices becomes increasingly important. Defects in transistors can cause partial or entire integrated circuit (IC) chip failure. Therefore, the ability to quickly and economically identify defects in the early stages of IC manufacturing can significantly reduce device design costs, shorten manufacturing iterations, minimize wafer scrap, and accelerate time to market. Probes are used to contact semiconductor and thin film materials to extract their electrical, mechanical, chemical, and optical properties. Summary of the Invention

[0005] The present disclosure generally relates to methods and techniques for determining when a probe tip is near or in contact with a sample surface or wafer.

[0006] In general, in one aspect, a method for determining when at least one probe having at least one probe tip approaches or contacts a sample surface includes mounting a probe chip having a probe and / or a sample on at least one movable stage. The method further includes instructing the movable stage to bring the at least one probe tip into proximity with or contact with the sample surface, while measuring a response signal caused by the probe tip approaching or contacting the sample surface.

[0007] According to one example, a set of fingers are integrally integrated with the probe.

[0008] According to one example, at least one side electrode is integrally integrated with the probe.

[0009] According to one example, a set of fingers are integrally integrated with the side electrodes.

[0010] According to one example, each finger in a set of fingers is separated by an air gap.

[0011] According to one example, the probe chip is a multi-probe chip.

[0012] According to one example, the response signal is measured when the probe and / or the sample is arranged under an objective lens of a microscope.

[0013] According to one example, the response signal is a capacitive response signal, and determining that the probe tip has contacted the sample surface further includes the following steps: (1) measuring the capacitance between the probe and at least one integrally integrated side electrode when the probe tip is not in contact with the sample surface; (2) instructing the stage to gradually move the probe tip into contact with the sample surface while measuring the capacitance between the probe and the side electrode at each step of movement of the stage; and (3) determining that contact is achieved when there is a difference between the capacitance measured when the probe tip is not in contact with the sample surface and the capacitance measured when the probe tip is in contact with the sample surface.

[0014] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0015] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0016] According to one example, the step movement of the stage is terminated when the capacitive response signal is equal to the set point capacitance.

[0017] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0018] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0019] According to one example, bringing the probe tip into contact with the sample surface includes the following steps: (1) selecting a reference position on the sample using a pattern recognition algorithm; (2) saving the pixel coordinates of the reference position in a memory of a computer; (3) identifying the probe tip using the pattern recognition algorithm and saving its pixel values; (4) instructing a translation stage to position the reference position below the probe tip; and (6) continuously adjusting the position of the translation stage to ensure that the probe tip is always positioned at the reference position on the sample surface.

[0020] According to one example, the response signal is an intensity response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) directing an incident light beam to one or more interdigitated air gaps between the probe and at least one integrally integrated side electrode; (2) measuring, using a photodetector, the intensity or position of a reflected light beam corresponding to the incident light beam when the probe tip is not in contact with the sample surface; (3) instructing a stage to gradually move the sample into contact with the probe tip while measuring the intensity or position of the reflected light beam at each step of movement of the stage; and (4) determining that contact has been achieved when there is a difference between the intensity or position of the reflected light beam measured when the probe tip is not in contact with the sample surface and the intensity or position of the reflected light beam measured when the probe tip is in contact with the sample surface.

[0021] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0022] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0023] According to one example, the stepwise movement of the stage is terminated when the intensity response signal is equal to the set point intensity.

[0024] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0025] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0026] According to one example, the response signal is a photocurrent response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) directing an incident light beam to one or more interdigitated air gaps between the probe and at least one integrally integrated side electrode; (2) using an integrally integrated photodetector to generate a photocurrent due to a transmitted light beam impinging on the integrally integrated photodetector, wherein the transmitted light beam is a transmitted portion of the incident light beam; (3) measuring the photocurrent when the probe tip is not in contact with the sample surface; (4) directing the stage to bring the sample into contact with the probe tip while measuring the photocurrent response signal at each step of the stage movement; and (5) determining that contact has been achieved when there is a difference between the photocurrent measured when the probe tip is not in contact with the sample surface and the photocurrent measured when the probe tip is in contact with the sample surface.

[0027] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0028] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0029] According to one example, the stepwise movement of the stage is terminated when the photocurrent response signal is equal to the set-point photocurrent.

[0030] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0031] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0032] According to one example, the response signal is a piezoresistive response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) measuring a piezoresistive corresponding to a deflection of the probe when the probe tip is not in contact with the sample surface using an integrally integrated piezoresistor of the probe; (2) instructing a stage to gradually move the probe tip into contact with the sample surface while measuring the deflection of the probe having the integrally integrated piezoresistive resistor at each step of movement of the stage; and (3) determining that contact is achieved when there is a difference between the piezoresistive measured when the probe tip is not in contact with the sample surface and the piezoresistive measured when the probe tip is in contact with the sample surface.

[0033] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0034] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0035] According to one example, the step movement of the stage is terminated when the piezoresistive response signal is equal to the set point piezoresistive.

[0036] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0037] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0038] According to one example, the response signal is a high-frequency response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) applying a high-frequency signal to the probe; (2) measuring the amplitude and / or phase of a transmission and / or reflection signal of the high-frequency signal when the probe tip is not in contact with the sample surface; (3) directing the stage to bring the probe tip into contact with the sample surface while measuring the amplitude and / or phase of the transmission and / or reflection signal of the probe at each step of movement of the stage; and (4) determining that contact is achieved when there is a difference between the amplitude and / or phase of the transmission and / or reflection signal measured when the probe tip is not in contact with the sample surface and the amplitude and / or phase of the transmission and / or reflection signal measured when the probe tip is in contact with the sample surface.

[0039] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0040] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0041] According to an example, the step movement of the stage is terminated when the amplitude and / or phase of the measured transmission and / or reflection signal is equal to a set point amplitude and / or phase of the transmission and / or reflection signal, respectively.

[0042] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0043] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0044] According to one example, the response signal is an elongation image response signal of the probe, and determining that the probe tip has contacted the sample surface includes the following steps: (1) capturing and observing the probe using a camera; (2) instructing a stage to gradually move the probe tip into contact with the sample surface while observing the probe at each step of the stage movement; (3) using a camera to observe the elongation of the probe due to the probe tip pushing against the sample surface; (4) when there is an elongation image of the probe, determining that contact has been achieved.

[0045] According to one example, the stepping movement of the stage is halted when the camera captures the extension of the probe.

[0046] According to one example, the stepping movement of the stage is terminated when the probe tip contacts the sample surface.

[0047] According to one example, terminating the stepping movement of the stage includes the following steps: (1) acquiring pixel coordinate values ​​of the probe tip and pixel coordinate values ​​of a reference position on the probe chip when the probe is not in contact with the sample surface; (2) calculating a tip reference length between the probe tip and the reference position; (3) instructing the stage to gradually move the probe tip into contact with the sample surface while calculating the tip reference length at each step of the stage movement; and (4) terminating the stepping movement of the stage when the tip reference length when the probe tip is in contact with the sample surface is greater than the tip reference length when the probe tip is not in contact with the sample surface.

[0048] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0049] According to one example, the stepping movement of the stage is terminated when a tip reference length between the probe tip and a reference position on the probe chip is equal to a set point pixel length.

[0050] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0051] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0052] According to one example, the response signal is a contrast response signal of the probe and / or sample, and determining that the probe tip has contacted the sample surface includes the following steps: (1) placing the probe and sample inside the electron microscope; (2) directing the stage to bring the sample into contact with the probe tip surface of the probe tip while monitoring a change in contrast or color of the probe and / or sample at each step of the stage movement; and (3) determining that contact is immediately achieved when there is a change in contrast or color of the probe and / or sample surface.

[0053] According to one example, the electron microscope is a scanning electron microscope or a transmission electron microscope.

[0054] According to one example, the stepwise movement of the stage is halted when there is a change in contrast or color of the probe and / or sample surface.

[0055] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0056] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0057] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0058] According to one example, the response signal is an electrical response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) applying an electrical signal to a probe integrated with a set of fingers; (2) connecting at least one integrally integrated side electrode integrated with the set of fingers to a signal measurement unit; (3) instructing a stage to gradually move the probe tip into contact with the sample surface; (4) pushing the probe tip against the sample surface until at least one of the set of fingers on the probe contacts a finger on the integrally integrated side electrode, so that the electrical signal is transferred from the probe to the integrally integrated side electrode; (4) using the signal measurement unit to measure the transfer of the electrical signal from the probe to the integrally integrated side electrode at each step of movement of the stage; and (5) determining that contact is achieved when there is a transfer of the electrical signal from the probe to the integrally integrated side electrode.

[0059] According to one example, the stepping movement of the stage is stopped when the signal measuring unit measures the electrical signal transferred from the probe.

[0060] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0061] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0062] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0063] According to one example, the response signal is a resonance response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) exciting the probe to resonate so that the probe vibrates; (2) measuring the resonance frequency, amplitude and / or phase of the probe when the probe tip is not in contact with the sample surface; (3) instructing the movable stage to gradually move the sample close to or in contact with the probe tip, while measuring the resonance frequency, amplitude and / or phase of the probe at each step of movement of the movable stage; (4) measuring the change in the resonance frequency, amplitude and / or phase of the probe when the probe tip approaches or contacts the sample surface; (5) when there is a change in the resonance frequency, amplitude and / or phase of the probe, determining that contact is achieved.

[0064] According to one example, the stepping movement of the stage is halted when there is a change in the resonant frequency, amplitude and / or phase of the probe.

[0065] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0066] According to one example, the stepping movement of the stage is terminated when the resonant frequency, amplitude and / or phase measured when the probe tip approaches or contacts the sample surface is equal to the set point frequency, amplitude and / or phase, respectively.

[0067] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0068] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0069] According to one example, the response signal is a current response signal, and determining that the probe tip has contacted the sample surface includes the following steps: (1) applying a potential difference between the sample and the probe tip; (2) measuring a current between the probe tip and the sample when the probe tip is not in contact with the sample surface; (3) instructing the stage to gradually move the probe tip into contact with the sample surface while measuring a current between the probe tip and the sample at each step of movement of the stage; (4) determining that contact is achieved when the current measured when the probe tip is not in contact with the sample surface is less than the current measured when the probe tip is in contact with the sample surface.

[0070] According to one example, the stepping movement of the stage is terminated when a current measured when the probe tip is not in contact with the sample surface is less than a current measured when the probe tip is in contact with the sample surface.

[0071] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0072] According to one example, the stepping movement of the stage is terminated when a contact resistance measured when the probe tip is in contact with the sample surface is equal to a set point contact resistance.

[0073] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact resistance at each location on the sample surface.

[0074] According to one example, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample after maintaining a constant contact resistance at each location on the sample surface.

[0075] According to one example, the probe chip is a multi-probe chip including a plurality of probes, each of the plurality of probes having a probe tip, and the response signal is an in-plane current response signal, and determining that the probe tips of the plurality of probes have contacted the sample surface includes the following steps: (1) applying a potential difference between at least two probes of the plurality of probes; (2) measuring an in-plane current flowing between the two probes having the applied potential difference when at least two probe tips corresponding to the at least two probes are separated from the sample surface; (3) instructing a stage to gradually move the at least two probe tips into contact with the sample surface while measuring the current flowing between the at least two probes having the applied potential difference at each step of movement of the stage; and (4) determining that contact is achieved when the in-plane current measured when the probe tips are not in contact with the sample surface is less than the in-plane current measured when the probe tips are in contact with the sample surface.

[0076] According to one example, the stepping movement of the stage is terminated when the in-plane current measured when the probe tip is not in contact with the sample surface is less than the in-plane current measured when the probe tip is in contact with the sample surface.

[0077] According to an example, after stopping the stepping movement of the stage, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0078] According to one example, the stepping movement of the stage is terminated when the in-plane current measured while the probe tip is in contact with the sample surface is equal to the set point current.

[0079] According to one example, the stepwise movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface.

[0080] According to one example, after maintaining a constant contact force at each location on the sample surface, mechanical, electrical, chemical, optical and / or photonic measurements are performed between the probe tip and the sample.

[0081] According to one example, the probe chip is a multi-probe chip including a plurality of probes, each of the plurality of probes having a probe tip, and the stage is directed to bring the probe tip into contact with or close to the sample surface.

[0082] According to one example, techniques of a capacitance response signal, an intensity response signal, a photocurrent response signal, a piezoresistive response signal, a high frequency response signal, an elongated image response signal, a contrast response signal, an electrical response signal, a resonance response signal, a current response signal, and / or an in-plane current response signal are used to determine when the probe tip contacts or is in proximity to the sample surface, and wherein the method further includes applying a probing signal to at least one of the probes to modulate charge transport in the sample.

[0083] According to one example, when a probing signal is applied, at least two probes of the plurality of probes are used to extract the conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance of the sample.

[0084] According to one example, a plot of the conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance of the sample versus the magnitude or phase of the probe signal is generated.

[0085] According to one example, at least one of the plurality of probes is shorter than other probes of the plurality of probes.

[0086] According to an example, the detection signal is a DC voltage, a high frequency signal, a magnetic signal, an optical signal or a photon signal.

[0087] According to one example, the probe carrying the detection signal is stationary.

[0088] According to one example, the probe carrying the detection signal is freely movable and shorter than one or more side probes; and when the detection signal is applied to the movable and shorter probe, at least two side probes are used to extract the conductivity, dielectric constant, resistance, resistivity, sheet resistance and / or 4-wire Kelvin resistance of the sample.

[0089] According to one example, a plot of the conductance, dielectric constant, resistance, resistivity, sheet resistance and / or 4-wire Kelvin resistance of the sample versus the amplitude or phase of the probe signal and / or versus the amplitude of the excitation voltage is generated.

[0090] According to one example, the probe carrying the probing signal is longer than one or more side probes.

[0091] According to one example, the probe carrying the detection signal is used to perform scanning probe microscopy.

[0092] According to one example, after performing scanning probe microscopy, a side probe is used to extract the conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance of the sample.

[0093] According to one example, at least one probe is used to capacitively couple a probe signal to the sample; and at least another probe is used to obtain a modified version of the probe signal; and one or more material properties of the sample are inferred using the modified version of the probe signal.

[0094] According to an example, the one or more material properties are resistivity, doping, electron and hole mobility, defects, carrier concentration, crystal structure and / or sheet resistance.

[0095] According to one example, the sample and the probe tip are placed in an electrolyte solution or gas environment.

[0096] According to one example, when a probing signal is applied to a middle probe of the plurality of probes, measurements of transfer curves, output curves, gate leakage curves, conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance are performed.

[0097] In various embodiments, a processor or controller may be associated with one or more storage media (collectively referred to herein as "memory," e.g., volatile and non-volatile computer memory, such as RAM, PROM, EPROM, EEPROM, floppy disks, CDs, optical disks, tapes, SSDs, etc.). In some embodiments, the storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. The various storage media may be fixed within the processor or controller, or may be removable so that one or more programs stored thereon can be loaded into the processor or controller to implement various aspects discussed herein. The terms "program" or "computer program" are used herein in a general sense to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors or controllers.

[0098] It should be understood that all combinations of the aforementioned concepts and the additional concepts discussed in more detail below (provided such concepts are not mutually inconsistent) are considered part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered part of the inventive subject matter disclosed herein. It should also be understood that terminology explicitly used herein, which may also appear in any disclosure incorporated by reference, should be given a meaning most consistent with the specific concepts disclosed herein.

[0099] These and other aspects of various embodiments will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] A more complete understanding and appreciation of the present invention will be obtained by reading the following detailed description in conjunction with the accompanying drawings, in which:

[0101] Figure 1A is a top view of a probe chip according to aspects of the present disclosure.

[0102] Figure 1B is a perspective view of a probe head assembly according to aspects of the present disclosure.

[0103] Figure 1C is a schematic diagram of a system for determining when a probe tip is near or in contact with a sample according to aspects of the present disclosure.

[0104] Figure 2is a perspective view of a multi-probe chip according to aspects of the present disclosure.

[0105] Figure 3 is a top view of a probe chip according to aspects of the present disclosure.

[0106] Figure 4 is a top view of a multi-probe chip according to aspects of the present disclosure.

[0107] Figure 5 is a top view of a multi-probe chip according to aspects of the present disclosure.

[0108] Figure 6A is a top view of a probe tip not in contact with a sample according to aspects of the present disclosure.

[0109] Figure 6B is a top view of a probe tip in contact with a sample according to aspects of the present disclosure.

[0110] Figure 7 is a flow chart of a method for determining when at least one probe tip is near or in contact with the same surface according to aspects of the present disclosure. DETAILED DESCRIPTION

[0111] This disclosure describes various methods and techniques for determining when a probe tip approaches or contacts a sample surface by monitoring a response signal (e.g., a capacitance response signal, an intensity response signal, a photocurrent response signal, a piezoresistive response signal, a high-frequency response signal, an elongation image response signal, a contrast response signal, an electrical response signal, a resonance response signal, a current response signal, and / or an in-plane current response signal). Upon contact, the probe tip can generate and maintain a constant contact force on the sample surface.

[0112] The ability to determine when the probe tip contacts the sample surface will mitigate situations where the probe tip accidentally penetrates the sample and damages both the sample and the probe tip.

[0113] Constant contact force probing (CCFP) is a technique in which a probe tip applies a known contact force to a sample surface. The contact force can be maintained using a feedback controller, such as a proportional-integral (PI) or proportional-integral-derivative (PID) controller. At each location on the sample surface where a constant contact force is achieved, electrical, mechanical, optical, photonic, and / or chemical measurements can be performed. A multi-probe, which is a single chip with multiple probe tips, can also be used to perform constant contact force probing.

[0114] The ability to maintain a constant contact force when electrically probing a sample ensures that a constant contact resistance is maintained between the probe tip and the sample, thereby improving the repeatability and reliability of the measurement.

[0115] Figure 1AA perspective view of a probe chip 100A is shown. The probe 102 can be made of a metal, an alloy, silicon, silicon nitride, silicon dioxide, a polymer, or a combination thereof. The probe 102, the fingers 106 and 108, and the side electrode 114 have a finite thickness, which is determined by the probe manufacturing process. The probe 102 includes a base 116, a set of fingers 106, and a probe tip 104. At least one side electrode 114 including a set of fingers 108 is integrally integrated with the probe 102. A horizontal air gap 110 and a vertical air gap 112 electrically isolate the probe 102 from the side electrode 114, respectively. The probe 102 is freely suspended on the substrate 120 and is movable, while the side electrode 114 is fixed.

[0116] Figure 1B is a perspective view of the probe head assembly 100B. Figure 1B , the probe chip 100A can be fixed and wire-bonded to a printed circuit board (PCB) 122. The PCB is inserted into a probe head 124. Contact pins in the probe head 124 contact the PCB 122. A cable 126 connects the contact pins to connection pins 130 of an ultra-miniature connector 128. The connection pins 130 are connected to test equipment. The test equipment can be a source measurement unit, a vector network analyzer 178, a parameter analyzer 184, a capacitance measurement unit 172, a transimpedance amplifier (TIA) 180, or a lock-in amplifier 182.

[0117] Figure 1C is a schematic diagram of a system for determining when the probe tip 104 is near or in contact with the sample 132. Specifically, Figure 1CThe interaction between the probe chip 100A, the sample 132, the microscope assembly 100C and various types of test equipment is shown. The probe head 124 is attached to the probe stage 142. The PCB 122 that houses the probe chip 100A is inserted into the probe head 124. The probe chip 100A is mounted at a certain angle relative to the sample 132 (such as a semiconductor wafer). The sample 132 is placed on the chuck 144, and the chuck 144 is placed on the Z stage 152. The Z stage 152 is placed on the rotating stage 154. The rotating stage 154 is placed on the XY translation stage 156. The XY translation stage 156 is screwed into the base plate 158. The stages 152, 154, 156 can be manual, piezoelectric or stepper motor driven. The probe stage 142, the Z stage 152, the rotation stage 154, and the XY translation stage 156 can be used individually or in combination to bring the sample 132 into contact with the probe tip 104, or to bring the probe tip 104 into contact with the sample 132. The knob 150 can be used to move the chuck 144 and the sample 132 closer to or away from the probe tip 104. A switch 148 turns on the microscope light source 138, and the knob 146 adjusts the intensity of the light source 138. The light source 138 is directed through the lens 140 to observe the probe tip 104 and the sample 132. The microscope 100C is also equipped with a camera 134 and an eyepiece 136 for observing the surface of the probe tip 104 and the sample 132. The microscope 100C can also be integrated with an incident beam port 168 and a photodetector port 170. The capacitance measurement unit 172, vector network analyzer (VNA) 178, transimpedance amplifier (TIA) 180, lock-in amplifier (LIA) 182, and / or parameter analyzer 184 are connected to the probe head 124 via the microminiature connector 128. A computer 100D is connected to the camera 134, the capacitance measurement unit 172, the incident beam unit 174, the photodetector unit 176, the VNA unit 178, the TIA unit 180, the LIA unit 182, and the parameter analyzer 184. A software program running on the computer 100D controls the measurement unit and analyzer. A graphical user interface (GUI) of the software program is displayed on the computer monitor 160. The GUI shows a panel 162 that displays an image of the probe chip 100A and the sample 132 captured by the camera 134. The GUI also shows another panel 164 that displays measurement data. A computer mouse 166 is connected to the computer 100D to receive user input.

[0118] Continue to refer Figure 1CThe probe 102 is mounted at an angle relative to the sample surface. The capacitance measurement unit measures the capacitance between the probe 102 and at least one side electrode 114 when the probe tip 104 is not in contact with the sample surface. This measured capacitance is referred to as a capacitance response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, while measuring the capacitance response signal with each stage movement. As the probe tip 104 pushes against the sample surface, the probe 102 can deflect in a lateral direction and / or out-of-plane direction relative to the fixed side electrode 114. When deflected out-of-plane, the probe 102 and its fingers 106 deflect in an out-of-plane direction relative to the fixed side electrode 114. This reduces the overlap area between the fingers 106 of the probe 102 and the fingers 108 of the side electrode 114, causing the capacitance measurement unit to measure a reduced capacitance. Contact is achieved when there is probe deflection, which results in a difference between the capacitance response signal when the probe tip 104 is not in contact with the sample surface and the capacitance response signal when the probe tip 104 is in contact with the sample surface.

[0119] There is a direct relationship between the capacitance response signal, the degree of probe deflection, and the contact force caused by probe tip 104 on the sample surface. The probe deflection, capacitance response signal, and contact force can be calibrated against a commercially available load cell. The load cell can be pushed against probe tip 104 with a known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while measuring the corresponding capacitance response signal. Calibration plots of capacitance response signal versus contact force and capacitance response signal versus displacement can be generated. Therefore, to maintain a constant contact force on the sample surface, probe tip 104 can be pushed against the sample surface until the measured capacitance response signal corresponds to the desired contact force on the calibrated capacitance response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample. It should be noted that contact between probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or camera. However, a microscope and / or camera are not required to bring probe tip 104 into contact with the sample surface.

[0120] Capacitive response signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0121] To perform constant contact force detection, a set-point capacitance corresponding to a desired contact force is selected from the capacitance response signal versus contact force plot. The stage is directed to bring the probe tip 104 into contact with the sample surface. When the capacitance response signal equals the set-point capacitance, constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0122] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the set-point capacitance and the capacitive response signal and process this difference. The processed capacitance difference is used to continuously adjust the movement of the stage to ensure that the capacitive response signal equals the set-point capacitance. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0123] Microscope 100C, as well as other testing equipment such as scanning electron microscopes (SEMs), transmission electron microscopes (TEMs), and probes, exhibit inherent drift due to varying coefficients of thermal expansion of the various components comprising the equipment. This drift in the equipment can cause the probe tip 104 or the sample to drift in the X, Y, and Z directions. Therefore, maintaining a constant contact force while compensating for this drift requires placing the probe 102 and / or sample on a translation stage. Computer vision programs can be deployed to track the probe tip 104 and continuously reposition it over areas of interest on the sample surface. In computer vision, software algorithms are used to process camera images to automatically identify and recognize features of interest. Computer vision, combined with robotics, provides autonomous navigation and data acquisition. Therefore, specifically for probing sample 132, movable stages 152, 154, and 156 are robotic components, while camera 134 captures images of probe 102 and sample 132, and software algorithms (such as pattern recognition) are applied to the images. Based on the information gathered from the captured images, the software instructs stages 152, 154, and 156 to move or remain stationary. Microscope 100C is equipped with a camera 134 and a computer 100D for capturing images or a video stream of the probe tip 104 and the region of interest. From the video stream, a pattern recognition algorithm can be used to determine one or more edges of the region of interest and select a reference position within the region of interest on the sample surface. The pixel coordinates of the reference position are calculated. The reference position can be the center of the region of interest. Next, the pixel coordinates of probe tip 104 are calculated using the pattern recognition algorithm or by clicking the tip with a mouse. The reference position and the pixel coordinate values ​​of probe tip 104 are saved. The pixel length between probe tip 104 and the reference position is calculated. Using the stepping motion of an XY stage calibrated relative to the pixel length, the probe tip 104 and the reference position can be continuously monitored, and the XY stage is translated to bring probe tip 104 to the reference position. Thereafter, the Z stage is directed to bring probe tip 104 into contact with the reference position, while a first feedback controller is used to ensure that a constant contact force is maintained between probe tip 104 and the sample surface. At any time, if the probe tip 104 or the sample drifts, the XY stage is translated to reposition the probe tip 104 at the reference position. A second feedback controller can be used to instruct the XY stage to move the reference position below the probe tip 104. The job of the second feedback controller is to continuously minimize the pixel length so that the probe tip is always at the reference position.

[0124] In another embodiment, the probe tip 104 is pushed against the sample surface, causing the probe 102 to deflect in the lateral direction. A capacitance or displacement measurement unit or meter can be connected between the probe 102 and the side electrode 114 to measure the capacitance when the probe tip 104 is pushed against the sample. All of the capacitive response signal techniques described above for determining when the probe tip 104 contacts the sample surface, constant contact force detection, and drift compensation can be applied to this embodiment.

[0125] In another embodiment, determining that the probe tip 104 has contacted the sample involves generating a light beam (e.g., a laser beam) using an incident beam unit 174. The light beam is transmitted through an incident beam port 168 on the microscope 100C. A lens 140 directs the incident light beam toward interdigitated fingers (formed by fingers 106 of the probe 102 and fingers 108 of the side electrodes 114), and the intensity and position of the reflected light beam are measured using a photodetector unit 176. The photodetector may be an orthogonal photodetector. The probe chip 100 and / or the sample may be mounted on at least one movable stage, which may be manually, piezoelectrically, or driven by a stepper motor. The probe 102 is mounted at an angle relative to the sample surface. When the probe tip 104 is not in contact with the sample surface, the intensity and position of the reflected light beam are transmitted to the photodetector unit 176 via the photodetector port 170. The intensity or position of the reflected light beam is converted into an intensity response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, while measuring the intensity response signal at each step of the stage movement. When the probe tip 104 is pushed against the sample surface, the probe 102 can be deflected in a lateral direction and / or an out-of-plane direction relative to the fixed side electrode 114. As the probe 102 deflects, different intensities or positions of the light beam are recorded by the photodetector. Contact is achieved when there is a difference between the intensity response signal when the probe tip 104 is not in contact with the sample surface and the intensity response signal when the probe tip 104 is in contact with the sample surface.

[0126] There is a direct relationship between the intensity response signal, the degree of probe deflection, and the contact force induced by probe tip 104 on the sample surface. The probe deflection, intensity response signal, and contact force can be calibrated against a commercially available load cell. The load cell can be pressed against probe tip 104 with known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while measuring the corresponding intensity response signal. Calibration plots of intensity response signal versus contact force and intensity response signal versus displacement can be generated. Therefore, to maintain a constant contact force on the sample surface, probe tip 104 can be pressed against the sample surface until the measured intensity response signal corresponds to the desired contact force on the calibrated intensity response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between probe tip 104 and the sample. It should be noted that contact between probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or camera.

[0127] The intensity responsive signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0128] To perform constant contact force probing, a set-point intensity corresponding to a desired contact force is selected from a plot of intensity response signal versus contact force. The stage is directed to bring the probe tip 104 into contact with the sample surface. When the intensity response signal equals the set-point intensity, constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0129] In situations where a constant contact force needs to be maintained for several seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the set point intensity and the intensity response signal and process this difference. The processed intensity difference is used to continuously adjust the movement of the stage to ensure that the intensity response signal is equal to the set point intensity. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0130] In another embodiment, a photodetector is integrally integrated with the probe 102 on the same substrate 120. The photodetector is located beneath the interdigitated fingers 106, 108. The photodetector can be a diode, a PN junction, or a PIN junction. A parameter analyzer 184 applies a potential difference across the integrally integrated photodetector, and the same parameter analyzer 184 measures the photocurrent flowing through the integrally integrated photodetector. Determining whether the probe tip 104 has contacted the sample involves generating an incident light beam using an incident light beam unit 174, transmitting the light beam through an incident light beam port 168 via a lens 140 to the integrally integrated photodetector, and measuring the photocurrent generated by the transmitted portion of the incident light beam that strikes the integrally integrated photodetector. The probe chip 100 and / or the sample can be mounted on at least one movable stage, which can be manually, piezoelectrically, or driven by a stepper motor. The probe 102 is mounted at an angle relative to the sample surface. When the probe tip 104 is not in contact with the sample surface, the photocurrent is recorded by the parameter analyzer 184. The photocurrent generated by the transmitted light beam striking the photodetector is called the photocurrent response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, while measuring the photocurrent response signal with each step of the stage movement. As the probe tip 104 pushes against the sample surface, the probe 102 can deflect in a lateral direction and / or an out-of-plane direction relative to the fixed side electrode 114. As the probe 102 deflects, the width of the air gaps 110 and 112 will change, causing the intensity of the transmitted light beam to change. As a result, the parameter analyzer 184 will record different photocurrents. Contact is achieved when there is a difference between the photocurrent response signal when the probe tip 104 is not in contact with the sample surface and the intensity response signal when the probe tip 104 is in contact with the sample surface.

[0131] There is a direct relationship between the photocurrent response signal, the degree of probe deflection, and the contact force induced by probe tip 104 on the sample surface. The probe deflection, photocurrent response signal, and contact force can be calibrated against a commercially available load cell. The load cell can be pushed against probe tip 104 with a known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while measuring the corresponding photocurrent response signal. Calibration plots of the photocurrent response signal versus contact force and the photocurrent response signal versus displacement can be generated. Therefore, to maintain a constant contact force on the sample surface, probe tip 104 can be pushed against the sample surface until the measured photocurrent response signal corresponds to the desired contact force from the calibrated photocurrent response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between probe tip 104 and the sample. It should be noted that contact between probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or camera.

[0132] The photocurrent response signaling technique allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0133] To perform constant contact force probing, a setpoint photocurrent corresponding to a desired contact force is selected from a plot of the photocurrent response signal versus contact force. The stage is directed to bring the probe tip 104 into contact with the sample surface. When the photocurrent response signal equals the setpoint photocurrent, constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip 104 and the sample.

[0134] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the setpoint photocurrent and the photocurrent response signal and process this difference. The processed photocurrent difference is used to continuously adjust the movement of the stage to ensure that the photocurrent response signal is equal to the setpoint photocurrent. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0135] In another embodiment, a piezoresistor is integrally integrated into the base 116 of the probe 102. Determining whether the probe tip 104 has contacted the sample involves measuring the probe's piezoresistance as the probe 102 deflects. The piezoresistor is configured as a 4-wire Kelvin structure. A parameter analyzer 184 is connected to the 4-wire Kelvin structure and supplies current through the outer electrodes while measuring the voltage drop across the middle electrode of the 4-wire Kelvin structure. The piezoresistance is calculated by dividing the measured voltage by the source current. The probe chip 100 may or may not have side electrodes 114. The probe chip 100 and / or the sample may be mounted on at least one movable stage, which may be manually driven, piezoelectrically driven, or driven by a stepper motor. The probe 102 is mounted at an angle relative to the sample surface. When the probe tip 104 is not in contact with the sample surface, the probe's piezoresistance is recorded by the parameter analyzer 184. The measured piezoresistance is referred to as the piezoresistive response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, and the piezoresistive response signal is measured with each step of the stage's movement. When the probe tip 104 is pushed against the sample surface, the probe 102 can deflect in a lateral direction and / or an out-of-plane direction relative to the fixed side electrode 114. As the probe 102 deflects, the parameter analyzer 184 will record different piezoresistances. Contact is achieved when there is a difference between the piezoresistive response signal when the probe tip 104 is not in contact with the sample surface and the piezoresistive response signal when the probe tip 104 is in contact with the sample surface.

[0136] There is a direct relationship between the piezoresistive response signal, the degree of probe deflection, and the contact force induced by the probe tip 104 on the sample surface. The probe deflection, piezoresistive response signal, and contact force can be calibrated against a commercially available load cell. The load cell can be pushed against the probe tip 104 with a known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to the probe tip 104 while measuring the corresponding piezoresistive response signal. Calibration plots of the piezoresistive response signal versus contact force and displacement can be generated. Therefore, to maintain a constant contact force on the sample surface with the probe tip 104, the probe tip 104 can be pushed against the sample surface until the measured piezoresistive response signal corresponds to the desired contact force from the calibrated piezoresistive response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample. It should be noted that contact between the probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or a camera.

[0137] The piezoresistive response signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0138] To perform constant contact force detection, a setpoint piezoresistive signal corresponding to a desired contact force is selected from a piezoresistive response signal versus contact force plot. The stage is directed to bring the probe tip 104 into contact with the sample surface. When the piezoresistive response signal equals the setpoint piezoresistive signal, constant contact force is achieved. Mechanical, electrical, chemical, optical, and / or photonic measurements can then be performed between the probe tip and the sample.

[0139] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the setpoint piezoresistance and the piezoresistive response signal and process this difference. The processed piezoresistive difference is used to continuously adjust the movement of the stage to ensure that the piezoresistive response signal is equal to the setpoint piezoresistive. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0140] In another embodiment, determining that the probe tip 104 has contacted the sample involves applying a high-frequency signal to the probe 102 using a vector network analyzer (VNA) 178 or similar equipment, and measuring the amplitude and / or phase of the reflected and / or transmitted high-frequency signal using the same VNA 178. The probe chip 100 may or may not have side electrodes 114. The probe chip 100 and / or the sample may be mounted on at least one movable stage, and the stage may be manually, piezoelectric, or stepper motor driven. The probe 102 is mounted at an angle relative to the sample surface. When the probe tip 104 is not in contact with the sample surface, the amplitude and phase of the reflected and / or transmitted high-frequency signal are recorded by the vector network analyzer 178. The measured amplitude and / or phase of the reflected and / or transmitted high-frequency signal is referred to as the high-frequency response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, while measuring the amplitude and / or phase of the high-frequency response signal at each step of the stage's movement. When the probe tip 104 contacts and pushes against the sample surface, the probe tip 104 transmits or reflects a high-frequency signal, causing the vector network analyzer 178 to measure different high-frequency response signals. Contact is achieved when there is a difference between the high-frequency response signal when the probe tip 104 is not in contact with the sample surface and the high-frequency response signal when the probe tip 104 is in contact with the sample surface.

[0141] There is a direct relationship between the amplitude and / or phase of the measured high-frequency response signal, the degree of probe deflection, and the contact force induced by probe tip 104 on the sample surface. The probe deflection, the amplitude and / or phase of the high-frequency response signal, and the contact force can be calibrated against a commercially available load cell. The load cell can be pressed against probe tip 104 with known contact forces and displacements. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while simultaneously measuring the corresponding amplitude and / or phase of the high-frequency response signal. Calibration plots of the amplitude and / or phase of the high-frequency response signal versus contact force, as well as calibration plots of the amplitude and / or phase of the high-frequency response signal versus displacement, can be generated. Therefore, to maintain a constant contact force on the sample surface, probe tip 104 can be pressed against the sample surface until the measured amplitude and / or phase of the high-frequency response signal corresponds to a desired contact force from a calibrated amplitude and / or phase of the high-frequency response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample. It should be noted that contact of the probe tip 104 with the sample surface may be performed under the guidance of a microscope and / or a camera.

[0142] The high frequency response signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0143] To perform constant contact force detection, a setpoint amplitude and / or phase of the high-frequency signal corresponding to a desired contact force is selected from a plot of amplitude and / or phase of the high-frequency response signal versus contact force. The stage is directed to bring the probe tip 104 into contact with the sample surface. Constant contact force is achieved when the amplitude and / or phase of the high-frequency response signal equals the setpoint amplitude and / or phase of the high-frequency signal. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0144] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the set point amplitude and / or phase of the high-frequency signal and the amplitude and / or phase of the high-frequency response signal and process the difference. The difference in the processed amplitude and / or phase of the high-frequency signal is used to continuously adjust the movement of the stage to ensure that the amplitude and / or phase of the high-frequency response signal is equal to the set point amplitude and / or phase of the high-frequency signal. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0145] In another embodiment, determining that the probe tip 104 has contacted the sample involves observing a change in contrast or color of the probe 102 and / or the sample. The probe chip 100 may or may not have side electrodes 114. The probe chip 100 and / or the sample may be mounted on at least one movable stage, and the stage may be manually, piezoelectrically, or driven by a stepper motor. The probe 102 is mounted at an angle relative to the sample surface. The probe 102 and the sample are mounted inside an electron microscope, such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). As the electron beam irradiates the probe 102 and the sample, the electron beam deposits charge on the probe and the sample. The stage is directed to bring the probe tip 104 into contact with the sample surface, while monitoring the change in contrast or color of the probe and / or the sample with each step of the stage's movement. When the probe tip 104 makes initial contact with the sample, a flow of charge occurs between the probe 102 and the sample. This charge flow can be considered a change in contrast or color of the probe and / or the sample. The change in contrast or color of the probe 102 and / or the sample is referred to as a contrast response signal. The SEM or TEM generates an image or video of the probe 102 and sample 132. The image is displayed in panel 162 of the GUI. By observing the color or contrast change from panel 162, stage movement can be terminated when there is a change in the color or contrast of the probe 102 and / or sample 132. A software algorithm can be used to monitor the change in contrast or color of the probe 102 and / or sample 132 and automatically instruct the stage to terminate movement. After terminating stage movement, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0146] The contrast variation technique allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0147] To perform constant contact force probing, the stage is instructed to apply a known overdrive to further push the probe tip 102 against the sample surface. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be made between the probe tip 102 and the sample.

[0148] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to determine the stage position when the probe tip 104 initially contacts the sample surface and instruct the stage to further apply a known stage overdrive. The feedback controller continuously adjusts the stage position to maintain the overdrive. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0149] In another embodiment, determining whether the probe tip 104 has contacted the sample involves measuring an electrical signal transferred between the probe 102 and the side electrode 114. The electrical signal can be a voltage. The probe chip 100 and / or the sample can be mounted on at least one movable stage, which can be manually, piezoelectrically, or driven by a stepper motor. The probe 102 is mounted at an angle relative to the sample surface. An electrical signal is applied to the probe 102 or the side electrode 114. As an example, a signal measurement unit is connected to the side electrode 114. The signal measurement unit can be a parameter analyzer 184. A first terminal of the parameter analyzer 184 applies the electrical signal to the probe 102, and the side electrode 114 is connected to a second terminal of the parameter analyzer 184. When the probe tip 104 is not in contact with the sample surface, an electrical reading is measured by the second terminal of the parameter analyzer 184. The electrical reading measured by the second terminal is referred to as an electrical response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface, while measuring the electrical response signal with each step of the stage's movement. When probe tip 104 is pushed against the sample surface, probe 102 may deflect in a lateral direction and / or out-of-plane direction relative to fixed side electrode 114. This probe deflection may cause fingers 106 to mechanically contact fingers 108, thereby causing an electrical signal to be transferred from probe 102 to side electrode 114. Contact is achieved when there is a difference between the electrical response signal when probe tip 104 is not in contact with the sample surface and the electrical response signal when fingers 106 and 108 are in mechanical and electrical contact.

[0150] There is a direct relationship between the degree of probe deflection and the contact force caused by probe tip 104 on the sample surface. The probe's deflection and contact force can be calibrated against commercially available load cells. The load cell can be pushed against probe tip 104 with known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while measuring the corresponding electrical response signals. Of interest is the contact force and displacement that causes fingers 106 and 108 to electrically short-circuit. Therefore, to maintain a constant contact force on the sample surface, probe tip 104 can be pushed against the sample surface until fingers 106 and 108 are electrically short-circuited. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between probe tip 104 and the sample. It should be noted that contact between probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or camera. However, a microscope and / or camera are not required to bring probe tip 104 into contact with the sample surface.

[0151] The electrical response signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0152] To perform constant contact force probing, the stage is directed to bring the probe tip 104 into contact with the sample surface. When an electrical response signal is present, a constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip 104 and the sample.

[0153] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to continuously adjust the movement of the stage to ensure that the fingers 106, 108 are always electrically shorted. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0154] In another embodiment, as in Figure 2 As shown in FIG, a multi-probe chip 200 is provided. A plurality of probes 102, 202 and side electrodes 114 are integrally integrated on the same substrate 120 (not shown). The probes 102, 202 are freely movable, and the side electrodes 114 are fixed. One or more capacitance measurement units can be applied between at least one probe 102 and at least one side electrode 114. The aforementioned capacitance response signal, intensity response signal, photocurrent response signal, piezoresistive response signal, high-frequency response signal, elongation image response signal, contrast response signal, electrical response signal, resonance response signal, current response signal and / or in-plane current response signal technology can be used to determine when the probe tip contacts or approaches the sample surface. A plurality of probes 102, 202 can also be used for constant force detection. In addition, the probe chip 200 can be used to extract sheet resistance or perform 4-wire Kelvin resistance measurement by providing current between the external probe tips 104 and measuring the voltage drop between the internal probe tips 204.

[0155] In the same Figure 3 In another embodiment shown in FIG, is a probe chip 300 having multiple comb drives. The probe 102 is freely movable. The first comb drive C1 includes a portion of the probe 102, fingers 106, air gaps 110 and 112, fingers 108, and side electrodes 114. The second comb drive C2 includes a beam 302, fingers 304, air gaps 308, fingers 306, and actuation electrodes 312. The beam 302 is connected to the probe 102 and a zigzag spring 310. The zigzag spring 310 and the beam 302 are also freely movable. When the probe tip 104 is pushed against the sample surface, the probe 102 may deflect in an out-of-plane direction, an in-plane direction, or a lateral direction. Comb drive 1 is similar to FIG. Figure 1A, and all of the techniques of capacitance response signal, intensity response signal, photocurrent response signal, piezoresistive response signal, high frequency response signal, elongation image response signal, contrast response signal, electrical response signal, resonance response signal, current response signal and / or in-plane current response signal can be used to determine when the probe tip contacts or approaches the sample surface. The probe chip 300 can also be used for constant force detection.

[0156] refer to Figure 3 In another embodiment, the meander springs 310 are piezoresistors or strain gauges, where their resistance varies with deflection of the probe 102. A load cell can be used to determine the relationship between probe deflection, contact force, and piezoresistance.

[0157] refer to Figure 3 In another embodiment, a bottom electrode 316 is present below the probe 102. An air gap exists between the bottom electrode and the probe 102. By connecting a capacitance measurement unit 172 between the probe 102 and the bottom electrode 316, the deflection of the probe 102 can be measured as a change in capacitance. If the probe tip 104 is pushed against the sample surface, the change in capacitance between the bottom electrode 316 and the probe 102 is proportional to the contact force applied by the probe tip 104 to the sample surface.

[0158] refer to Figure 3 In another embodiment, a top electrode 318 is present above the probe 102. An air gap exists between the top electrode 318 and the probe 102. By connecting a capacitance measurement unit 172 between the probe 102 and the top electrode 318, the deflection of the probe 102 can be measured as a change in capacitance. If the probe tip 104 is pushed against the sample surface, the change in capacitance between the top electrode 318 and the probe 102 is proportional to the contact force applied by the probe tip 104 to the sample surface. Contact vias 320 connect the top electrode 318 to a metal electrode (not shown). The metal electrode is connected to the capacitance measurement unit 172.

[0159] refer to Figure 3 In another embodiment, by using a lock-in amplifier 182 (see Figure 1C ) applies a combination of AC and DC signals to the electrodes 312, which causes the beam 302 to vibrate electrostatically, thereby exciting the probe 102 to resonate. The parameter analyzer 184 (see Figure 1C ) is used to apply a potential difference between the probe 102 and at least one side electrode 114. The vibration of the probe 102 generates a motional current between the probe 102 and the side electrode 114. A transimpedance amplifier 180 (see Figure 1C) can convert the motional current into a motional voltage. The lock-in amplifier 182 can then be used to process the motional voltage to extract the resonant frequency, phase, and amplitude of the vibrating probe 102. As the probe tip 104 approaches the sample surface, its resonant frequency, phase, and / or amplitude may change due to the attractive and repulsive forces between the probe tip 104 and the sample surface. When the probe tip 104 initially contacts the sample surface, the resonant amplitude will remain constant. By tracking the resonant amplitude, phase, and / or frequency, it is possible to detect when the probe tip 104 initially contacts the sample surface.

[0160] refer to Figure 3 Determining that the probe tip 104 has contacted the sample surface involves the steps of exciting the probe 102 to resonate and measuring and tracking the probe's resonant frequency, amplitude, and / or phase. The probe chip 300 and / or the sample can be mounted on at least one movable stage, and the stage can be manual, piezoelectric, or stepper motor driven. The probe 102 is mounted at a certain angle relative to the sample surface. When the probe tip 104 is not in contact with the sample surface, its resonant frequency, phase, and / or amplitude are measured. The measured resonant frequency, phase, and / or amplitude are referred to as the resonance response signal. The stage is directed to bring the probe tip 104 close to or into contact with the sample surface, while measuring the resonance response signal at each step of the stage's movement. When the probe tip 104 pushes against the sample surface, the probe 102 can deflect in a lateral direction and / or out-of-plane direction relative to the fixed side electrode 114. When the probe 102 deflects due to contact with the sample surface, different resonance response signals will be measured. Contact is achieved when there is a difference between the resonance response signal when the probe tip 104 is not in contact with the sample surface and the resonance response signal when the probe tip 104 is in contact with the sample surface.

[0161] There is a direct relationship between the resonance response signal, the degree of probe deflection, and the contact force induced by probe tip 104 on the sample surface. The probe deflection, resonance response signal, and contact force can be calibrated against a commercially available load cell. The load cell can be pressed against probe tip 104 with a known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to probe tip 104 while measuring the corresponding resonance response signal. Calibration plots of the resonance response signal versus contact force and the resonance response signal versus displacement can be generated. Therefore, to maintain a constant contact force on the sample surface with probe tip 104, probe tip 104 can be pressed against the sample surface until the measured resonance response signal corresponds to the desired contact force from the calibrated resonance response signal versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between probe tip 104 and the sample. It should be noted that contact between probe tip 104 and the sample surface can be performed under the guidance of a microscope and / or a camera. Furthermore, the probe 102 may be non-resonant, and changes in its vibration frequency, phase, and / or amplitude may be used to determine when the probe tip contacts the sample surface.

[0162] The resonant response signal technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0163] To perform constant contact force detection, a setpoint frequency, amplitude, and / or phase corresponding to a desired contact force is selected from the resonance response signal versus contact force plot. The stage is directed to bring the probe tip 104 into contact with the sample surface. When the resonance response signal equals the setpoint frequency, amplitude, and / or phase, a constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0164] In situations where a constant contact force needs to be maintained for several seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the set point frequency, phase, and / or amplitude and the resonant response signal. The feedback controller then processes the difference between the set point value and the resonant response signal and uses the processed difference to continuously adjust the movement of the stage to ensure that a constant contact force is maintained on the sample surface. By doing so, the probe tip 104 can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0165] refer to Figure 3In another embodiment, the probe chip 300 can be used as a force or displacement sensor. The second comb drive C2 acts as a linear variable capacitor, whose capacitance changes linearly with the force applied to the probe tip 104 in the in-plane direction. The applied force can be measured by connecting a capacitance or displacement measurement unit between the probe 102 and the electrode 312. When the probe tip 104 is pushed in the in-plane direction, the capacitance at the second comb drive C2 will increase due to the increase in the overlapping area of ​​the fingers 304 and 306. When the probe tip 104 is extended in the in-plane direction, the capacitance of the second comb drive C2 will decrease due to the decrease in the overlapping area of ​​the fingers 304 and 306. The probe chip 300 can also be used for nanoindentation measurement.

[0166] Refer to Figure 1- Figure 5 In another embodiment, current feedback is used to bring the probe tip 104 and / or side probe tips 204, 404 into contact with the sample surface. This technique works well if the probes 102, 402, 406, the probe tips 104, 204, 404, and the sample are conductive. Determining that the probe tip 104, 204, 404 has contacted the sample involves the following steps: applying a potential difference between at least one probe 102, 402, 406 and the sample using a parameter analyzer 184, and measuring the current between the probe 102, 402, 406 and the sample using the same parameter analyzer 184. The probe chip 100, 200, 300, 400, 500 and / or the sample can be mounted on at least one movable stage, and the stage can be manual, piezoelectric, or stepper motor driven. The probes 102, 402, 406 are mounted at an angle relative to the sample surface. When the probe tips 104, 204, 404 are not in contact with the sample surface, the current between the probes 102, 402, 406 and the sample is measured. The measured current is referred to as the current response signal. The stage is directed to bring at least one probe tip 104, 204, 404 into contact with the sample surface, while measuring the current response signal with each step of the stage's movement. As the probe tips 104, 204, 404 contact and push against the sample surface, current will flow between the probes and the sample. Contact is achieved when there is a difference between the current response signal when the probe tips are not in contact with the sample surface and the current response signal when the probe tips 104, 204, 404 are in contact with the sample surface.

[0167] There is a direct relationship between the measured current response signal, the degree of probe deflection, and the contact force induced by the at least one probe tip 104, 204, 404 on the sample surface. The probe deflection, current response signal, and contact force can be calibrated against a commercially available load cell. A conductive sample is mounted on the load cell, and a potential difference is applied between the sample and the at least one probe tip. The sample on the load cell can be pushed against the at least one probe tip with a known contact force and displacement. The load cell can be instructed to apply different contact forces and displacements to the at least one probe tip while measuring the corresponding current response signal. Calibration plots of the current response signal versus contact force and the current response signal versus displacement can be generated. Based on the current response signal versus displacement plot, a constant contact resistance versus displacement plot can be generated. As the probe tip 104, 204, 404 pushes against the sample surface, at some point the contact resistance will level off, such that further advancement of the probe tip 104, 204, 404 into the sample does not result in a significant change in the contact resistance or current response signal. Thus, in order to maintain a constant contact resistance of the probe tip 104, 204, 404 on the sample surface, the probe tip 104, 204, 404 can be pushed against the sample surface until the contact resistance stabilizes. Once the desired contact force and contact resistance are achieved, the movement of the stage can be stopped and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the at least one probe tip 104, 204, 404 and the sample. It should be noted that the contact of the at least one probe tip 104, 204, 404 with the sample surface can be performed under the guidance of a microscope and / or a camera.

[0168] Current-responsive signaling technology allows at least one probe tip to safely contact conductive and semi-conductive samples while maintaining the integrity of the probe tip and sample.

[0169] To perform constant contact resistance probing, a set-point resistance corresponding to a desired contact resistance is selected from a constant contact resistance versus displacement plot. The stage is directed to bring at least one probe tip into contact with the sample surface. When the measured contact resistance equals the set-point resistance, constant contact resistance is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the at least one probe tip and the sample.

[0170] In situations where a constant contact resistance needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the setpoint resistance and the measured contact resistance and process this difference. The feedback controller uses this processed resistance difference to continuously adjust the movement of the stage to maintain a constant force on the sample while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0171] refer to Figure 4 and Figure 5 In another embodiment, an in-plane current response signal technique is used to bring the side probe tips 204, 404 into contact with the sample surface. The in-plane current response signal technique works well when the sample and the probe tips 204, 404 are conductive. Determining that all side probe tips 204, 404 have contacted the sample surface involves applying a potential difference to at least two of the side probes 402, 406 using a parameter analyzer 184, and measuring the current between the two side probes 402, 406 to which the potential difference has been applied using the same parameter analyzer 184. The probe chip 400, 500 and / or the sample can be mounted on at least one movable stage, which can be manual, piezoelectric, or stepper motor driven. The probe chip 400, 500 is mounted at an angle relative to the sample surface. To bring the probe tips 104, 204, 404 into contact with the sample surface, an alignment procedure is performed to ensure that all side probe tips 104, 204, 404 are in contact with the sample surface upon contact. When the probe tips 104, 204, 404 are not in contact with the sample surface, the current is measured between the side probes 402, 406 to which a potential difference has been applied. The measured current is referred to as the in-plane current response signal. The stage is directed to bring the probe tips 104, 204, 404 into contact with the sample surface, while measuring the in-plane current response signal with each step of the stage movement. When the probe tips 104, 204, 404 contact and push against the sample surface, current will flow between at least two side probes 204, 404. Contact is achieved when there is a difference between the in-plane current response signal when the probe tips 104, 204, 404 are not in contact with the sample surface and the in-plane current response signal when the probe tips are in contact with the sample surface.

[0172] The in-plane current response signal technique allows the probe tip 104, 204, 404 to safely contact conductive and semi-conductive samples while maintaining the integrity of the probe tip 104, 204, 404 and the sample.

[0173] To perform constant contact force probing, a setpoint current corresponding to the desired contact force is selected. The stage is directed to bring the side probe tip 204, 404 into contact with the sample surface. When the in-plane current response signal equals the setpoint current, constant contact force is achieved. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip 104, 204, 404 and the sample.

[0174] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the setpoint current and the in-plane current response signal and process the difference. The feedback controller uses the processed current difference to continuously adjust the movement of the stage to maintain a constant force on the sample while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip 104, 204, 404 and the sample.

[0175] refer to Figure 4 In another embodiment, a multi-probe chip 400 is provided. The multi-probe chip 400 includes a probe chip 300 with integrated side probes 402 and 406. Techniques of capacitance response signals, intensity response signals, photocurrent response signals, piezoresistive response signals, high-frequency response signals, elongation image response signals, contrast response signals, electrical response signals, resonance response signals, current response signals, and / or in-plane current response signals can be used to determine when the probe tips 104, 204, 404 contact the sample surface. The multi-probe chip 400 can be used to perform scanning probe microscopy, conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance measurements. The middle probe 102 is freely movable, and the side probes 402 and 406 are fixed. Side probes 402 and 406 can be used for conductance, dielectric constant, resistance, resistivity, sheet resistance and / or 4-wire Kelvin resistance measurements, while middle probe 102 can be used for scanning probe microscopy (SPM) measurements, such as atomic force microscopy (AFM), scanning tunneling microscopy (STM), and nanoindentation.

[0176] refer to Figure 4 In another embodiment, the middle probe 102 is used to perform SPM measurements on the sample surface, and the acquired image is used to guide contact positioning of the side probe tips 204, 404 on the sample surface. Thereafter, conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance measurements can be performed on the sample.

[0177] refer to Figure 4 In another embodiment, the middle probe 102 can be retracted in an in-plane direction by applying an excitation voltage to the electrode 312 using the parameter analyzer 184. The middle probe 102 can be retracted to be shorter than the side probes 402, 406.

[0178] refer to Figure 4In another embodiment, a multi-probe chip 400 is used to perform non-contact detection of a sample 132. The probe chip 400 is mounted perpendicular to the sample surface. The probe chip 400 and / or the sample 132 are mounted on a movable stage, and a lock-in amplifier 182 is used to excite the intermediate probe 102 to resonance or non-resonance. The stage is directed so that the intermediate probe tip 104 approaches the sample surface. When the intermediate probe tip 104 approaches the sample surface, its resonant frequency, phase and / or amplitude will change. The change in resonant frequency, phase and / or amplitude can be used to position the probe tips 104, 204 and 404 near the sample surface without direct contact with the sample surface. Electrical signals can be capacitively coupled to the sample from the probe tips 104, 204, 404 to characterize the mechanical, electrical, chemical, optical and / or photonic properties of the sample. A high-frequency signal can be applied to the intermediate probe 102 to implement scanning microwave impedance microscopy (SMIM), wherein the dielectric constant and conductivity of the sample can be extracted using the probe tip 104. Can be by supplying a detection signal to one of probe tips 104,204,404, and obtaining a modified version of the detection signal with at least one of the remaining probe tips 104,204,404, to study the charge transfer mechanism in the sample. The detection signal can be capacitively coupled to the sample, and according to the material properties of the sample, the modified detection signal will be obtained by at least one second probe tip 104,204,404. The modified detection signal can have different phases and / or amplitudes. The modified detection signal can contain important information about the sample, such as doping, electron and hole mobility, defects, carrier concentration, crystal structure, resistivity and many other information. The detection signal can be a DC voltage, a high frequency signal, a magnetic signal, an optical signal or a photon signal. By integrating a magnetic field into a measuring device, Hall effect, charge tunneling effect and Van der Pauw (Van der Pauw) measurement can be carried out on the sample. The intermediate probe 102 can include a magnetic material, such as nickel or cobalt, which can induce a magnetic field on the sample.

[0179] refer to Figure 5In another embodiment, a multi-probe chip 500 is provided. The multi-probe chip 500 includes a probe chip 300 with integrated side probes 402 and 406. Techniques such as capacitance response signals, intensity response signals, photocurrent response signals, piezoresistive response signals, high-frequency response signals, elongation image response signals, contrast response signals, electrical response signals, resonance response signals, current response signals, and / or in-plane current response signals can be used to determine when the probe tips 104, 204, 404 contact the sample surface. The middle probe 102 is designed to be shorter than the side probes 402 and 406. The middle probe 102 can be fixed or movable. The probe tips 104, 204, 404 can be used to extract the resistance, conductance, and / or dielectric constant of the sample. The sheet resistance, resistivity, and 4-wire Kelvin resistance of the sample can also be extracted using the probe tips 104, 204, 404. By bringing the side probe tips 204, 404 into contact with the sample surface, the middle probe 102 can be used to gate the transport of charge in the sample. For example, to measure the resistance, sheet resistance, and / or 4-wire Kelvin resistance of a sample, the side probe tips 204, 404 are in contact with the sample surface while an air gap exists between the sample surface and the middle probe tip 104. A parameter analyzer 184 is used to provide a current to the outer probe 402, and the voltage drop across the inner probe 406 is measured using the same parameter analyzer 184. To adjust the conductance, dielectric constant, resistance, sheet resistance, and / or 4-wire Kelvin resistance of the sample, a probe signal can be applied to the middle probe 102 while the conductance, dielectric constant, resistance, sheet resistance, and / or 4-wire Kelvin resistance of the sample is measured by the side probe tip. The middle probe 102 now acts as a gate electrode carrying the probe signal. Changing the amplitude and / or phase of the probe signal can change the conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance of the sample. Parametric measurements can be performed, whereby the sample's conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or four-wire Kelvin resistance are measured each time the amplitude and / or phase of the probe signal changes. A plot of the sample's conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or four-wire Kelvin resistance versus the amplitude or phase of the probe signal can be generated. The probe signal can be a DC voltage, a high-frequency signal, a magnetic signal, an optical signal, or a photon signal. The probe signal can also alter the sample's optical, mechanical, electrical, photonic, and / or chemical properties. The side probe tip 404 contacts the sample surface while the middle probe tip 104 is in close proximity to the sample surface, forming a transistor configuration. This transistor configuration can be used to rapidly study charge transport mechanisms in thin film materials and semiconductors. This transistor configuration eliminates the need to photolithographically pattern and deposit metal electrodes on thin film materials to form solid-state transistors before performing transistor output and transfer curve measurements. The combination of side probes 402 and 406 on the left and right sides of the middle probe 102 can serve as source or drain electrodes, respectively. The middle probe 102 will be the gate electrode.One of the side probe tips 204, 404 may also be dedicated to contacting the bulk or backside of the sample.

[0180] refer to Figure 5 The intermediate probe 102, beam 302, and meandering spring 310 are freely movable. Modulation of the optical, mechanical, electrical, photonic, and / or chemical properties of the sample can be achieved by applying a probe signal to the intermediate probe 102 while simultaneously moving the intermediate probe 102 toward or away from the sample surface. Movement of the probe tip 104 toward the sample surface can be achieved by applying an excitation voltage to the side electrode 114 using the parameter analyzer 184. It should be noted that in order to use the side electrode 114 as an actuator, the probe 102 should be designed such that the width of the air gap 110 is smaller than the air gap 502. The excitation voltage, a potential difference, is applied between the intermediate probe 102 and the side electrode 114, resulting in an electrostatic attraction force. This electrostatic attraction force tends to move the probe tip 104 closer to the sample surface. Parametric measurements can be performed where, at each step of the intermediate probe tip's position, the amplitude of the probe signal can be varied while simultaneously measuring the sample's conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance. The detection signal can be a DC voltage, a high-frequency signal, a magnetic signal, an optical signal, or a photon signal. A graph of the sample's conductivity, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance versus excitation voltage amplitude and a graph of the detection signal amplitude can be generated. Additionally, a graph of the sample's conductivity, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance versus excitation voltage amplitude can be generated. Finally, a graph of the sample's conductivity, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance versus detection signal amplitude can be generated.

[0181] refer to Figure 5The air gap between the middle probe tip 104 and the sample can be filled with ambient air, vacuum, other gases, polymers, fluids, electrolytes, etc. In the case of an electrolyte, the multi-probe 500 and the sample can be used as an ion-sensitive field effect transistor (ISFET). A gate dielectric layer is deposited on the sample surface. With or without any metal electrodes patterned on the sample surface, the side probe tips 204 and 404 contact the sample surface. The side probe tips 204 and 404 can penetrate the gate dielectric to contact the sample, or the dielectric layer can be first removed at the point where the side probe tips contact the sample. The sample and the probe tips 104, 204, 404 are placed in the electrolyte, wherein the gap between the middle probe tip 104 and the sample is filled with the electrolyte. At least one stage brings the sample into contact with the probe tip 104, 204, 404, and techniques such as capacitance response signals, intensity response signals, photocurrent response signals, piezoresistive response signals, high-frequency response signals, elongation image response signals, contrast response signals, electrical response signals, resonance response signals, current response signals, and / or in-plane current response signals can be used to determine when the probe tip is in contact with or near the sample surface. The middle probe tip 104 serves as the gate electrode, and a pair of side probe tips 204, 404 on the left and right sides of the middle probe 102 serve as the drain and source electrodes, respectively. Output curves and transfer curves of the transistor are performed on the sample. When the conductive side probe tips 204, 404 are in contact with the sample, in the output curve measurement, a voltage sweep is performed between the source and drain electrodes while the amplitude of the gate voltage (i.e., the probe signal) on the conductive middle probe 102 is step-adjusted. The gate voltage adjusts the channel conductance (i.e., charge transfer) in the sample directly below the dielectric layer. The current flowing between the drain and source electrodes versus the drain and source electrode voltage sweeps constitute the output curve. On the other hand, in the transfer curve measurement, a voltage sweep is performed between the gate electrode and the source electrode while the amplitude of the drain electrode voltage is step-adjusted. The current flowing between the drain electrode and the source electrode versus the gate electrode and source electrode voltage sweep constitutes a transfer curve. In addition, the gate leakage current can be monitored by plotting the current flowing between the gate electrode and the source electrode versus the gate electrode and source electrode voltage sweep. The source electrode can be electrically grounded during the output curve, transfer curve, and gate leakage curve measurements. The described ISFET detection configuration can be used for biosensing, where biological entities (such as antibodies) can be immobilized on a dielectric layer, and further binding of the antigen to the antibody may result in changes in the output, transfer, and gate leakage curves. The described transistor detection configuration can also be used for gas-sensitive field-effect transistors (GSFETs), where the probe tip 104, 204, 404 and the sample are placed in a gas environment, and the gap between the intermediate probe tip and the sample is filled with a gas of interest. Introducing different gases into the sample will change its output curve, transfer curve, and leakage current curve.Additionally, for ISFET and GSFET configurations, conductance, dielectric constant, resistance, resistivity, sheet resistance, and / or 4-wire Kelvin resistance measurements may be performed with the side probe tips 204 , 404 when a probing signal is applied to the middle probe 102 .

[0182] refer to Figure 4 and Figure 5 Each probe 102, 402, 406 can be used as a source electrode, a drain electrode, a gate electrode, or a body electrode of a transistor. The body electrode can apply a back bias to the sample.

[0183] refer to Figure 4 and Figure 5 , the multi-probe chips 400, 500 may be designed so that the middle probe 102 is located next to the outer probes 402. The plurality of probes 102 may also be integrally integrated into the multi-probe chips 400 and 500. The probes 102 may be fixed or freely movable.

[0184] refer to Figure 6A and Figure 6B In another embodiment, determining that the probe tip 104 has contacted the sample involves the step of observing an elongated image of the probe 102. The probe chip 200 may or may not have side electrodes 114. The probe chip 200 and / or the sample may be mounted on at least one movable stage, and the stage may be manual, piezoelectric, or stepper motor driven. The probe 102 is mounted at an angle relative to the sample surface. A microscope equipped with a camera is used to observe the probe and sample surface. The microscope may be an optical, scanning electron, or transmission electron microscope. When the probe tip 104 is not in contact with the sample surface, a video stream or image of the probe 102 is recorded, as in Figure 6A The recorded image is called an image response signal. The stage is directed to bring the probe tip 104 into contact with the sample surface while recording a new image response signal at each stage movement. When the probe tip 104 contacts and pushes against the sample surface, the probe tip 104 will deflect, resulting in an elongated image of the probe 102, as in Figure 6B Contact is achieved when there is a difference between the image response signal when the probe tip 104 is not in contact with the sample surface and the elongated image response signal when the probe tip 104 is in contact with the sample surface. Figure 6A and Figure 6B, plane AA represents edge 118 of substrate 120. Plane BB represents the position of probe tip 104 when the probe tip is not in contact with sample 132. Plane CC is the new position of probe tip 104 after probe tip 104 is pushed against sample surface 132. The distance between planes BB and CC represents the elongation of the probe caused by the deflection of probe 102 when in contact with sample surface 132. It should be noted that contact of probe tip 104 with the sample surface can be performed without a microscope or camera.

[0185] Once the desired probe extension image is captured, the user can manually or automatically stop the probe tip 104 from overdriving into the sample surface. To automatically stop pushing the probe tip 104 into the sample, computer vision techniques can be used. When the probe tip 104 is not in contact with the sample, its pixel coordinates can be recorded. This can be done by using a computer mouse 166 (see Figure 1C ) Click on the computer monitor 160 (see Figure 1C ) on the probe image 162 (see Figure 1C ) to select and save the probe tip 104 coordinates. Then, the reference position on the probe chip 200 can be selected with the mouse. The reference position is a fixed position on the probe chip 200. For example, the reference position can be one of the fixed probe fingers 108, or a position on the fixed edge 118 of the substrate 120 on which the probe 102 is manufactured. The distance between the probe tip 104 and the reference position is calculated in pixels (AB). This distance is called the tip reference length (AB). The stage is instructed to bring the probe tip 104 into contact with the sample surface, while calculating the tip reference length for each step of the stage's movement. The probe tip 104 is pushed against the sample surface until the probe is visually extended and the calculated tip reference length (AC) exceeds the tip reference length (AB). At this point, the stage stops moving, and the desired mechanical, electrical, chemical, optical and / or photonic measurements can be performed between the probe tip and the sample.

[0186] There is a direct relationship between the extended tip reference length (AC), the degree of probe deflection, and the contact force induced by the probe tip 104 on the sample surface. The probe deflection, extended tip reference length (AC), and contact force can be calibrated against a commercially available load cell. The load cell can be pushed against the probe tip 104 with known contact forces and displacements. The load cell can be instructed to apply different contact forces and displacements to the probe tip 104 while calculating the corresponding tip reference lengths. Calibration plots of tip reference length versus contact force and tip reference length versus displacement can be generated. Therefore, to maintain a constant contact force on the sample surface, the probe tip 104 can be pushed against the sample surface until the calculated extended tip reference length (AC) corresponds to the desired contact force from the calibrated tip reference length versus contact force plot. Once the desired contact force is achieved, stage movement can be halted, and mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0187] The extended tip reference length technology allows the probe tip 104 to safely contact conductive, semi-conductive, and non-conductive samples while maintaining the integrity of the probe tip and the sample.

[0188] To perform constant contact force probing, a set-point tip reference length corresponding to a desired contact force is selected from a tip reference length versus contact force graph. The stage is directed to bring the probe tip 104 into contact with the sample surface. Constant contact force is achieved when the extended tip reference length (AC) equals the set-point tip reference length. Thereafter, mechanical, electrical, chemical, optical, and / or photonic measurements can be performed between the probe tip and the sample.

[0189] In situations where a constant contact force needs to be maintained for seconds, minutes, hours, or days, a first feedback controller can be used. The goal of the feedback controller is to calculate the difference between the set-point tip reference length and the extended tip reference length (AC) and process this difference. The processed tip reference length difference is used to continuously adjust the movement of the stage to ensure that the calculated extended tip reference length (AC) is equal to the set-point tip reference length. By doing so, the probe tip can induce a constant contact force on the sample surface for a longer duration while performing mechanical, electrical, chemical, optical, and / or photonic measurements between the probe tip and the sample.

[0190] It should be noted that all the techniques and measurement methods described can be performed in the presence of a magnetic field. Once a magnet is integrated into the setup, Hall effect and charge tunneling measurements can also be performed on the sample.

[0191] Additionally, it should be noted that multiple techniques can be used simultaneously to determine when the probe tip 104 contacts the sample. As an example, the current response signal and the capacitance response signal can be used simultaneously to determine when the probe tip contacts the sample.

[0192] Finally, it should be noted that there are multiple ways to determine when the probe 102 with the probe tip 104 contacts the sample surface and perform constant contact force detection. The methods described in this application are not intended to limit the use of other innovative methods to achieve the desired results.

[0193] Figure 7 7 is a flow chart of a method 700 for determining when at least one probe tip approaches or contacts a sample surface. The method 700 includes mounting a probe chip having probes and / or a sample on at least one movable stage 702. The method 700 further includes instructing the movable stage to bring the at least one probe tip into proximity with or contact with the sample surface, while measuring a response signal 704 caused by the probe tip approaching or contacting the sample surface.

[0194] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0195] In other words, the indefinite articles "a" and "an" as used herein in the specification and claims should be understood to mean "at least one" unless explicitly stated otherwise.

[0196] As used herein in the specification and claims, the phrase "and / or" should be understood to mean "either or both" of the elements so coupled, i.e., elements that are present in some cases in combination and in other cases in isolation. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so coupled. Other elements may optionally be present in addition to the elements specifically identified by the "and / or" clause, whether or not related to those elements specifically identified.

[0197] As used herein in the specification and claims, "or" should be understood to have the same meaning as "and / or" defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one, but also including more than one, multiple or series of elements, and optionally additional unlisted items. Only terms that clearly indicate the contrary, such as "only one" or "exactly one", or when used in the claims, "consisting of...", will refer to including exactly one element of a plurality or series of elements. In general, the term "or" as used herein should only be interpreted as indicating an exclusive choice (e.g., "one or the other, but not both") when preceded by an exclusive term (e.g., "any one", "only one", or "exactly one").

[0198] As used herein in the specification and claims, with respect to a list of one or more elements, the phrase "at least one" should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements and does not exclude any combination of elements in the list of elements. This definition also allows that elements may optionally be present in addition to the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether or not related to those elements specifically identified.

[0199] It should also be understood that in any method claimed herein that includes more than one step or action, the order of the steps or actions of the method is not necessarily limited to the order in which the steps or actions of the method are recited unless explicitly stated to the contrary.

[0200] In the claims and the foregoing description, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "maintaining," "consisting of," etc., are to be understood as open-ended, i.e., meaning including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" are to be considered closed or semi-closed transitional phrases, respectively.

[0201] The above-described examples of the described subject matter can be implemented in any of a variety of ways. For example, some aspects can be implemented using hardware, software, or a combination thereof. When any aspect is implemented at least partially in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or computer or distributed across multiple devices / computers.

[0202] The present disclosure may be implemented as a system, method, and / or computer program product at any possible level of integrated technical detail. The computer program product may include a computer-readable storage medium (or medium) having computer-readable program instructions thereon for causing a processor to implement aspects of the present disclosure.

[0203] A computer-readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing devices. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are recorded, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be interpreted as being a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0204] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network can include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium within the corresponding computing / processing device.

[0205] The computer-readable program instructions for performing the operation of the present disclosure can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data of an integrated circuit, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and procedural programming languages ​​such as "C" programming language or similar programming languages. The computer-readable program instructions can be implemented entirely on the user's computer, partially implemented on the user's computer, as an independent software package, partially implemented on the user's computer and partially implemented on a remote computer, or implemented entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, by using the Internet of an Internet service provider). In some examples, the electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA) or a programmable logic array (PLA) can implement the computer-readable program instructions by personalizing the electronic circuit using the state information of the computer-readable program instructions to perform aspects of the present disclosure.

[0206] Aspects of the present disclosure are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to examples of the present disclosure. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0207] Computer-readable program instructions can be provided to a processor of a special-purpose computer or other programmable data processing apparatus to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus create a device for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, which can direct the computer, programmable data processing apparatus, and / or other device to operate in a particular manner, such that the computer-readable storage medium having the instructions stored therein comprises an article of manufacture, which comprises the instructions for implementing aspects of the functions / actions specified in the blocks of the flowchart and / or block diagram.

[0208] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operating steps to be performed on the computer, other programmable apparatus, or other device, thereby producing a computer-implemented process, such that the instructions executed on the computer, other programmable apparatus, or other device implement the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0209] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions and operations of the systems, methods and computer program products according to various examples of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, segment or portion of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some alternative embodiments, the functions annotated in the box may not occur in the order annotated in the figure. For example, the two boxes shown in succession can actually be implemented substantially simultaneously, or these boxes can sometimes be implemented in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart and the combination of the boxes in the block diagram and / or flowchart can be implemented by a system based on special-purpose hardware, which performs a specified function or action or performs a combination of special-purpose hardware and computer instructions.

[0210] Other implementations are within the scope of the following claims and other claims to which the applicant is entitled.

[0211] Although various examples have been described and illustrated herein, a person of ordinary skill in the art will readily devise various other means and / or structures for performing the functions and / or obtaining the results and / or one or more advantages described herein, and each of these variations and / or modifications is considered to be within the scope of the examples described herein. More generally, a person skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are exemplary, and that actual parameters, dimensions, materials, and / or configurations will depend on the specific application in which the teachings are used. A person skilled in the art will recognize or be able to ascertain, using only routine experimentation, many equivalents to the specific examples described herein. Therefore, it should be understood that the foregoing examples are presented by way of example only, and that, within the scope of the appended claims and their equivalents, the examples may be implemented in a manner other than as specifically described and claimed. Examples of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the scope of the present disclosure.

Claims

1. A method for determining when at least one probe having at least one probe tip is in proximity to or in contact with a sample surface of a sample, comprising the steps of: Mounting a probe chip having probes and / or a sample on at least one movable stage; as well as The movable stage is instructed to bring at least one probe tip close to or into contact with the sample surface, while measuring a response signal caused by the probe tip close to or into contact with the sample surface.

2. The method according to claim 1, wherein A set of fingers are integrally integrated with the probe.

3. The method according to claim 2, wherein: Each finger in the set of fingers is separated by an air gap.

4. The method according to claim 1, wherein At least one side electrode is integrally integrated with the probe.

5. The method according to claim 4, wherein A set of fingers are integrally integrated with the side electrodes.

6. The method according to claim 1, wherein The probe chip is a multi-probe chip.

7. The method according to claim 1, wherein The response signal is measured when the probe and / or the sample is arranged under the objective of a microscope.

8. The method according to claim 1, wherein The response signal is a capacitive response signal, and determining that the probe tip has contacted the sample surface further comprises the following steps: measuring a capacitance between the probe and at least one integrally integrated side electrode when the probe tip is not in contact with the sample surface; instructing a stage to gradually move the probe tip into contact with the sample surface while measuring the capacitance between the probe and the side electrode at each step of the stage movement; and When there is a difference between the capacitance measured when the probe tip is not in contact with the sample surface and the capacitance measured when the probe tip is in contact with the sample surface, it is determined that contact is achieved.

9. The method according to claim 1, wherein Bringing the probe tip into contact with the sample surface comprises the following steps: selecting a reference location on the sample using a pattern recognition algorithm; storing the pixel coordinates of the reference position in a memory of a computer; identifying the probe tip using the pattern recognition algorithm and saving its pixel value; instructing one or more translation stages to position the reference position below the probe tip; instructing the one or more translation stages to bring the probe tip into contact with the reference position; and The position of the translation stage is continuously adjusted to ensure that the probe tip is always positioned at a reference position on the sample surface.

10. The method according to claim 1, wherein The response signal is an intensity response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: directing an incident light beam into one or more interdigitated air gaps between the probe and at least one integrally integrated side electrode; measuring, using a photodetector, an intensity or position of a reflected light beam corresponding to an incident light beam when the probe tip is not in contact with the sample surface; instructing a stage to gradually move the sample into contact with the probe tip while measuring the intensity or position of the reflected light beam at each step of movement of the stage; and Contact is determined to be achieved when there is a difference between the measured intensity or position of the reflected light beam when the probe tip is not in contact with the sample surface and the measured intensity or position of the reflected light beam when the probe tip is in contact with the sample surface.

11. The method according to claim 1, wherein The response signal is a photocurrent response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: directing an incident light beam into one or more interdigitated air gaps between the probe and at least one integrally integrated side electrode; generating a photocurrent due to a transmitted light beam impinging on the integrally integrated photodetector using an integrally integrated photodetector, wherein the transmitted light beam is a transmitted portion of the incident light beam; measuring a photocurrent when the probe tip is not in contact with the sample surface; directing a stage to bring the sample into contact with the probe tip while measuring a photocurrent response signal at each step of movement of the stage; and When there is a difference between the photocurrent measured when the probe tip is not in contact with the sample surface and the photocurrent measured when the probe tip is in contact with the sample surface, it is determined that contact is achieved.

12. The method according to claim 1, wherein The response signal is a piezoresistive response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: measuring, using an integrally integrated piezoresistor of the probe, a piezoresistance corresponding to a deflection of the probe when the probe tip is not in contact with the sample surface; instructing a stage to gradually move the probe tip into contact with the sample surface while measuring the deflection of the probe having the integrally integrated piezoresistor at each step of movement of the stage; and Contact is determined to be achieved when there is a difference between the measured piezoresistance when the probe tip is not in contact with the sample surface and the measured piezoresistance when the probe tip is in contact with the sample surface.

13. The method according to claim 1, wherein The response signal is a high-frequency response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: applying a high-frequency signal to the probe; measuring the amplitude and / or phase of the transmission and / or reflection signal of the high-frequency signal when the probe tip is not in contact with the sample surface; directing a stage to bring the probe tip into contact with the sample surface while measuring the amplitude and / or phase of the transmission and / or reflection signals of the probe at each step of movement of the stage; and Contact is determined to be achieved when there is a difference between the amplitude and / or phase of the transmission and / or reflection signals measured when the probe tip is not in contact with the sample surface and the amplitude and / or phase of the transmission and / or reflection signals measured when the probe tip is in contact with the sample surface.

14. The method according to claim 1, wherein The response signal is an elongation image response signal of the probe, and determining that the probe tip has contacted the sample surface comprises the following steps: capturing and observing the probe using a camera; instructing a stage to gradually move the probe tip into contact with the sample surface while observing the probe with each step of the stage's movement; using the camera to observe extension of the probe due to the probe tip pushing against the sample surface; and When there is an elongated image of the probe, it is determined that contact is achieved.

15. The method according to claim 1, wherein The response signal is a contrast response signal of the probe and / or the sample, and determining that the probe tip has contacted the sample surface comprises the following steps: placing the probe and the sample inside an electron microscope; directing a stage to bring the sample into contact with the probe tip surface of the probe tip while monitoring a change in contrast or color of the probe and / or sample at each step of movement of the stage; and Contact is determined to be imminent when there is a change in contrast or color of the probe and / or the sample surface.

16. The method according to claim 1, wherein The response signal is an electrical response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: applying an electrical signal to a probe integrated with a set of fingers; connecting at least one integrally integrated side electrode with the set of fingers to a signal measurement unit; an indicator stage to gradually move the probe tip into contact with the sample surface; pushing the probe tip against the sample surface until at least one of a set of fingers on the probe contacts a finger on the integrally integrated side electrode, causing the electrical signal to transfer from the probe to the integrally integrated side electrode; measuring, using the signal measuring unit, a transfer of the electrical signal from the probe to the integrally integrated side electrode at each step of movement of the stage; and Contact is determined to be achieved when there is transfer of the electrical signal from the probe to the integrally integrated side electrode.

17. The method according to claim 1, wherein The response signal is a resonance response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: Exciting the probe to resonate, causing the probe to vibrate; measuring the resonant frequency, amplitude, and / or phase of the probe when the probe tip is not in contact with the sample surface; instructing the movable stage to gradually move the sample into proximity with or contact with the probe tip while measuring the resonant frequency, amplitude, and / or phase of the probe at each step of movement of the movable stage; measuring changes in the resonant frequency, amplitude, and / or phase of the probe when the probe tip approaches or contacts the sample surface; and Contact is determined to be achieved when there is a change in the resonant frequency, amplitude and / or phase of the probe.

18. The method according to claim 1, wherein The response signal is a current response signal, and determining that the probe tip has contacted the sample surface comprises the following steps: applying a potential difference between the sample and the probe tip; measuring a current between the probe tip and the sample when the probe tip is not in contact with the sample surface; instructing a stage to gradually move the probe tip into contact with the sample surface while measuring the current between the probe tip and the sample at each step of movement of the stage; and When the current measured when the probe tip is not in contact with the sample surface is smaller than the current measured when the probe tip is in contact with the sample surface, it is determined that contact is achieved.

19. The method according to claim 1, wherein The probe chip is a multi-probe chip including a plurality of probes, each of the plurality of probes having a probe tip, and the response signal is an in-plane current response signal, and determining that the probe tips of the plurality of probes have contacted the sample surface comprises the following steps: applying a potential difference between at least two probes of the plurality of probes; measuring an in-plane current between two probes having an applied potential difference when at least two probe tips corresponding to the at least two probes are separated from the sample surface; instructing a stage to gradually move the at least two probe tips into contact with the sample surface while measuring a current between the at least two probes having an applied potential difference at each step of movement of the stage; and Contact is determined to be achieved when the measured in-plane current when the probe tip is not in contact with the sample surface is less than the measured in-plane current when the probe tip is in contact with the sample surface.

20. The method according to claim 1, wherein The probe chip is a multi-probe chip including a plurality of probes, each of the plurality of probes having a probe tip, and the stage is directed to bring the probe tip into contact with or into proximity with the sample surface.

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