CN114487607A - A kind of variable temperature heterogeneous interface contact resistivity testing device and testing method - Google Patents

Abstract

The invention discloses a variable temperature heterogeneous interface contact resistivity test device and a test method. The test device includes a probe test platform for controlling the scanning of a micrometer probe on the surface of a sample to be tested; and includes: a micrometer probe seat for Clamping the micrometer probe; variable temperature clamping bench, used to clamp and heat the sample to be tested; image acquisition module, used to collect the surface image information of the sample to be tested; displacement control unit, used to control the micrometer probe to be Measure the movement of the sample surface; including the X displacement module, the Y displacement module and the Z displacement module; the X displacement module and the Z displacement module are connected to the micrometer probe base, and the Y displacement module is connected to the temperature-variable clamping bench ; Resistance measurement unit, connected to the variable temperature clamping stage and the micrometer probe. The invention adopts the three-probe method, heating temperature control technology and machine vision to accurately correct the probe positioning, and can accurately measure the interface contact resistivity between the electrode material and the thermoelectric material under different temperature field conditions.

Description

A kind of variable temperature heterogeneous interface contact resistivity test device and test method

technical field

The invention relates to the technical field of electrical performance measurement, in particular to a contact resistivity test device and a test method for a variable temperature heterogeneous interface.

Background technique

Semiconductor devices always have interface contacts between heterogeneous materials such as semiconductor materials and metal alloy electrodes. Different from the physical effects in the semiconductor body, these surface and interface physical effects have a great impact on the characteristic parameters, stability and reliability of the device. influences. In particular, the fabrication of ohmic-like contacts is always done in the packaging process at the later stage of device fabrication. Device failure due to interface resistance will greatly increase production costs and losses. Therefore, the characterization of contact resistivity of heterogeneous interfaces such as metal/semiconductor has a significant technology. significance and economic value.

For example, thermoelectric refrigeration technology is a technology based on the Peltier effect that can realize directional heat transport and active refrigeration. Since this technology uses the electrons inside the material as the heat carrier, it has the advantages of high temperature control accuracy, full static state, high reliability, and easy integration. Features. Compared with traditional passive cooling methods such as air cooling, water cooling, and heat pipes, thermoelectric cooling technology also has ultra-high cooling density and cooling rate, and does not require complicated auxiliary mechanisms and external field conditions. Therefore, thermoelectric cooling technology has become one of the most promising technologies for active cooling of optoelectronic chips and other high-power chip hot spots, which is of great significance for the development of the semiconductor chip industry in the future.

The hetero interface of thermoelectric devices is usually a sandwich structure of multi-layer composites such as thermoelectric materials, barrier layers, transition layers, solders, and electrodes, and the thickness of each layer reaches the micron level. The function of the barrier layer is to block the mutual diffusion and chemical reaction between the thermoelectric material and the electrode layer to form a stable interface layer; the function of the transition layer is to play the function of the activation layer, promote the combination of the thermoelectric material and the electrode, and improve the bonding strength; the solder is the filler for welding The thermoelectric material is tightly connected with the electrode to realize the conduction of current and heat flow. However, due to the limitation of machining accuracy, the mutual contact between the heterointerfaces of thermoelectric devices often only occurs in some discrete local areas, and the actual contact area is much smaller than the theoretical area, which affects the electrical transfer between the interfaces and forms interface resistance. The interface resistance seriously restricts the cooling performance of the thermoelectric device. For example, in the steady-state operation mode of the thermoelectric device, the maximum temperature difference ΔT _steady,max , the cooling capacity Q _C and the cooling efficiency coefficient COP will be reduced; Cold temperature difference ΔT _{transient,max} and exacerbated temperature overshoot ΔT _overshoot . Therefore, it is necessary to characterize the contact resistance of the heterointerface of thermoelectric devices, and the results can be used as a reference for the control of interface resistance, optimize the manufacturing process of thermoelectric devices and improve the simulation theoretical model, establish the interface resistance optimization standard, and realize the low resistance and high reliability of thermoelectric particles and electrodes. Heterogeneous interface connections.

At present, the experimental measurement data of the interface resistivity of the hetero-interface of semiconductor devices is single, usually a fixed measurement value at room temperature. However, under actual working conditions, the interface resistivity will change with the change of temperature. Small changes will greatly affect the cooling performance of thermoelectric devices. The fixed measurement value at room temperature is not sufficient to characterize the interface resistivity, so it cannot be established more comprehensively and accurately. Optimal control method of interfacial resistance. At the same time, the thickness of the hetero interface of the thermoelectric device reaches the micrometer level, and the conventional control method is used to drive the motor to drive the probe to perform precise step scanning. The path interval is too large or inaccurate, resulting in a large error in the interface resistivity extracted from the relationship between the scan path and the resistance value. For example, Chinese patent CN 108508273 A discloses a device and method for directly measuring interface contact resistivity, which is characterized in that the sample to be tested is installed on the sample test fixture, a fixed current is provided for both ends of the sample, and a conventional control method is used to drive a motor to drive The probe performs precise step scanning and obtains the voltage, and finally converts to obtain the relationship between the scanning path and the resistance value at room temperature. However, this method can only obtain a fixed interface resistivity at room temperature, and cannot directly measure the interface resistivity corresponding to different temperatures under actual working conditions. Since the interface resistivity will change with the change of temperature under actual working conditions, a small change will greatly affect the cooling performance of the thermoelectric device. The fixed measurement value at room temperature is not sufficient to characterize the interface resistivity, and cannot be established more comprehensively and accurately. Optimal control method of interfacial resistance. At the same time, the thickness of the hetero interface of the thermoelectric device reaches the micrometer level. Due to the swing between the probe arm and the probe, the achievable probe positioning accuracy is low, and the scanning path interval is too large or inaccurate, resulting in the relationship between the scanning path and the resistance value. The interface resistivity error extracted from the curve graph is large. Therefore, there is still an urgent need for a test device and method for accurately measuring the contact resistivity of the interface between the electrode material and the thermoelectric material under different temperature field conditions.

SUMMARY OF THE INVENTION

In view of the disadvantages of the above thermoelectric device hetero interface contact resistivity testing technology, the present invention provides a variable temperature heterogeneous interface contact resistivity testing device and testing method, which adopts the three-probe method and heating temperature control technology to simulate the actual temperature field of the thermoelectric device. Working conditions, accurately measure the contact resistivity of heterogeneous interfaces such as metal/semiconductor under different temperature field conditions, which is of reference significance for optimizing the manufacturing process of thermoelectric devices and perfecting the simulation theoretical model; for thermoelectric devices, semiconductor packaging interconnection and other electronic components interface Electrical performance characterization has potential application value.

To achieve the above object, the technical scheme adopted in the present invention is:

On the one hand, the present invention proposes a contact resistivity test device of variable temperature heterogeneous interface, comprising:

A probe test platform, used to control the scanning of the micrometer probe on the surface of the sample to be tested; including: a micrometer probe seat, used to hold the micrometer probe; a temperature-variable clamping stand, used to clamp and heat the test sample a sample; an image acquisition module for collecting surface image information of the sample to be tested;

A displacement control unit for controlling the movement of the micrometer probe on the surface of the sample to be tested; including an X displacement module, a Y displacement module and a Z displacement module; wherein the X displacement module and the Z displacement module is connected with the micrometer probe base, and the Y displacement module is connected with the temperature-variable clamping bench;

The resistance measuring unit is connected with the temperature-variable clamping stage and the micrometer probe.

Preferably, the temperature-variable clamping stand includes a first power interface, a second power interface, a heater for clamping and heating the sample to be measured, and a temperature-measuring thermocouple; the temperature-measuring thermocouple is disposed in contact with the heater One end of the sample to be tested; the first power interface is electrically connected to the resistance test unit and the sample to be tested to form a closed loop; the sample to be tested is arranged on the first power interface and the between the two power ports.

Preferably, the temperature-variable clamping stage further includes a base, a bracket for fixing the heater, and a hand-clamping mechanism for adjusting the clamping tightness of the sample to be tested; the bracket includes a fixing A bracket and a sliding bracket; the hand-operated clamping mechanism is arranged on the base and connected with the sliding bracket.

Preferably, the hand-operated clamping mechanism includes a hand wheel and a sliding block; the sliding block is arranged on the base and is fixedly connected to the sliding bracket; the hand-operated wheel is drivingly connected to the sliding block .

Preferably, the heater is selected from any one of alumina ceramics, aluminum nitride ceramics and silicon nitride ceramics with built-in heating wires; the heater is wrapped with a copper heat transfer block, and the sample to be tested passes through The copper heat transfer block forms a closed loop with the first power interface and the second power interface; the temperature measuring thermocouple is arranged at one end of the copper heat transfer block that contacts the sample to be measured;

Preferably, the micrometer probe seat is made of low thermal conductivity insulating and heat-resistant materials, such as zirconia ceramics, glass fiber composite materials, and polytetrafluoroethylene;

Preferably, the micro-probe is made of tungsten.

Preferably, a PID controller is also included, and the PID controller realizes precise temperature control of the heater according to the temperature information collected by the temperature measuring thermocouple; the temperature control range of the heater is from room temperature to 800°C, The temperature control accuracy is preferably within ±1°C.

Preferably, the image acquisition module includes an optical imaging system for acquiring surface image information of the sample to be tested; the light source of the optical imaging system illuminates the sample to be tested, in some specific embodiments , the optical imaging system is an industrial camera;

Preferably, the image acquisition module further includes an XYZ imaging fine-tuning module for fine-tuning the focus of the optical imaging system.

Preferably, the resistance measurement unit includes a voltage-stabilized and constant-current power supply and a data acquisition module; the voltage-regulated and constant-current power supply is electrically connected to the first power interface to supply power to the sample to be tested; the data acquisition module It is connected with the second power interface and the micrometer probe, and is used for measuring the contact voltage between the sample to be tested and the micrometer probe.

Preferably, it also includes a computer unit for reading the surface image information of the sample to be tested collected by the image acquisition module, reading the information of the data acquisition module, and for setting the displacement control unit. moving parameters, controlling the focus of the XYZ imaging fine-tuning module; the optical imaging system collects the surface image information of the sample to be tested and inputs it into the computer, and positions the micrometer probe as the closed-loop correction information of the displacement control unit;

In the technical solution of the present invention, the movement of the displacement control unit is controlled by the computer unit, and the precision thereof can reach 1 μm or less.

Preferably, the pixels of the industrial camera are not less than 20 million pixels. In the technical solution of the present invention, after the closed-loop correction of the displacement control unit is performed by an industrial camera with more than 20 million pixels, the micrometer sensor The positioning accuracy of the needle can reach 0.5μm or less.

Preferably, the test process of the test device needs to be completed under vacuum conditions; in some specific embodiments, the test device further includes a vacuum cover, and during the test, a vacuum pump is used to evacuate the cover to a vacuum , the vacuum degree of the vacuum is less than or equal to 10Pa.

In another aspect, the present invention provides a test method using the above-mentioned variable temperature heterogeneous interface contact resistivity test device, comprising the following steps:

(1) install the sample to be tested in the temperature-variable clamping bench, and heat the sample to be tested;

(2) collecting the surface image of the sample to be tested, setting the scanning path and scanning step size, and generating the target position of the micron probe;

(3) Scanning measurement, the micrometer probe performs a resistance measurement every step, draws a graph of the relationship between the scanning path and the voltage value, and calculates the contact resistance R _c of the heterogeneous interface under the heating temperature. According to the sample to be tested The geometric parameters and the contact resistance R _c are calculated to obtain the contact resistivity ρ _c of the hetero interface at the heating temperature.

Further, the test method of the variable temperature heterogeneous interface contact resistivity test device specifically includes the following steps:

Step 1, clamp the sample to be tested in the temperature-variable clamping bench, and shake the hand wheel to clamp the sample to be tested;

Step 2., connecting the first power supply interface with a voltage-stabilized and constant-current power supply to provide a fixed current for the sample to be tested;

Step 3., set the heating temperature to the heater, and the temperature measuring thermocouple collects the temperature of the heater and feeds it back to the PID controller, and the precise temperature control of the heater is controlled by the PID controller;

Step 4., connect the data acquisition module with the micrometer probe and the second power interface, and set the scanning interval of the micrometer probe on the surface of the sample to be measured by the computer unit;

Step ⑤, scanning measurement, with the movement of the micrometer probe, the optical imaging system collects the surface image information of the sample to be tested and inputs it into the computer, and positions the micrometer probe as the closed-loop correction information of the displacement control unit. Scan the corresponding voltage of the measurement, and generate a curve diagram of the relationship between the scanning path and the voltage value in the computer;

Step ⑥, according to the curve diagram of the relationship between the scanning path and the voltage value and the fixed current value passing through the sample to be tested, calculate the contact resistance R _c of the heterogeneous interface under the temperature;

Step ⑦, adjust the heating temperature of the heater, and repeat steps ③-⑥ to obtain the contact resistance of the heterogeneous interface under different temperature field conditions; calculate the temperature-variable heterogeneous interface in combination with the cross-sectional area size S of the sample to be tested contact resistivity.

In the technical solution of the present invention, the calculation formula for calculating the contact resistivity of the temperature-variable interface is ρ _c =R _c ×S.

The above technical scheme has the following advantages or beneficial effects:

Aiming at the disadvantages of the thermoelectric device hetero interface contact resistivity testing technology in the prior art, the present invention provides a temperature-variable hetero interface contact resistivity testing device and testing method, which adopts the three-probe method, heating temperature control technology and machine Vision can accurately correct the positioning of the probe, and can accurately measure the interface contact resistivity between the electrode material and the thermoelectric material under different temperature field conditions.

Among them, the three-probe method and heating temperature control technology can be used to simulate the actual temperature field conditions of the thermoelectric device, and the corresponding contact resistivity can be obtained by measuring, which has great reference value for optimizing the manufacturing process of the thermoelectric device and perfecting the simulation theoretical model; With vision and positioning probe technology, the industrial camera can capture images and identify the position of the probe as a high-precision closed-loop correction information for the positioning probe. The positioning accuracy of the probe can reach below 0.5μm, which greatly improves the test accuracy of contact resistivity. .

Description of drawings

FIG. 1 is a schematic structural diagram of a contact resistivity testing device for a variable-temperature heterogeneous interface provided in Embodiment 1 of the present invention.

2 is a schematic structural diagram of a temperature-variable clamping bench of the temperature-variable hetero-interface contact resistivity testing device provided in Embodiment 1 of the present invention.

3 is a partial (A) enlarged view of the temperature-variable clamping bench of the temperature-variable hetero-interface contact resistivity testing device provided in Embodiment 1 of the present invention.

FIG. 4 is a graph showing the relationship between the scan path and the resistance value in Embodiment 2 of the present invention.

FIG. 5 is a graph showing the relationship between the scan path and the resistance value in Embodiment 3 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that when the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear. ”, etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation , constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a Removable connection, or integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or an internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example 1:

In view of the disadvantages of the thermoelectric device hetero-interface contact resistivity testing technology in the prior art, the present invention provides a temperature-variable hetero-interface contact resistivity testing device, as shown in Figures 1-3: including:

The probe test platform is used to control the scanning of the micrometer probe 51 on the surface of the sample 53 to be tested; including: a micrometer probe seat 4 for holding the micrometer probe 51 ; a temperature-variable clamping stand 5 for holding and heating the sample to be tested 53; the image acquisition module 6 is used to collect the surface image information of the sample to be tested 53;

The displacement control unit is used to control the movement of the micrometer probe 51 on the surface of the sample to be tested 53; including the X displacement module 2, the Y displacement module 3 and the Z displacement module 1; wherein the X displacement module 2 and the Z displacement module 1 is connected with the micrometer probe base 4, and the Y displacement module 3 is connected with the variable temperature clamping bench 5;

The resistance measurement unit is connected to the temperature-variable clamping stage 5 and the micrometer probe 51 .

During the use of the device provided by the present invention, the sample to be tested 53 is installed in the temperature-variable clamping bench 5, and the X displacement module 2 and the Y displacement module 3 control the movement of the micrometer probe seat 4 to realize the micrometer probe 51 moves on the horizontal plane; the Y displacement module 3 adjusts the height of the sample to be tested 53 by controlling the temperature-variable clamping stage 5 .

Further, the temperature-variable clamping stand 5 includes a first power interface 52-1, a second power interface 52-2, a heater 54 for clamping and heating the sample to be measured 53, and a temperature measuring thermocouple 55; the temperature measuring thermocouple 55 It is arranged at one end of the heater 54 that contacts the sample to be tested 53; the first power interface 52-1 is electrically connected with the resistance test unit and the sample to be tested 53 to form a closed loop; the sample to be tested 53 is arranged on the first power interface 52- 1 and the second power interface 52-2.

In the device provided by the present invention, the heater 54 is used to heat the sample 53 to be tested, so as to measure the contact resistivity at different temperatures, and the temperature of the sample to be tested 53 can be monitored by setting the temperature measuring thermocouple 54 .

Further, the temperature-variable clamping stage 5 also includes a base 59, a bracket 56 for fixing the heater 54, and a hand-clamping mechanism for adjusting the clamping tightness of the sample 53 to be tested; the bracket 56 includes a fixing bracket 56- 1 and the sliding bracket 56-2; the hand-operated clamping mechanism is arranged on the base 59 and is connected with the sliding bracket 56-2.

In the device provided by the present invention, during use, the distance between the sliding bracket 56-1 and the sliding bracket 56-2 can be adjusted by the hand-clamping mechanism. Measure the clamping tightness of the sample 53.

Preferably, the hand-crank clamping mechanism includes a hand wheel 57 and a sliding block 58 ; the sliding block 58 is arranged on the base 59 and is fixedly connected with the sliding bracket 56 - 2 ;

The device provided by the present invention adopts the cooperation of the hand wheel 57 and the slider 58. During use, the slider 58 is moved toward or away from the fixed bracket 56-1 by shaking the hand wheel 57, thereby shortening or increasing the sliding movement. The distance between the bracket 56-2 and the fixed heater and the fixed bracket 56-1 and the fixed heater can be used to measure samples of different specifications and adjust the clamping degree of the sample 53 to be tested.

Further, the heater 54 is selected from any one of alumina ceramics, aluminum nitride ceramics and silicon nitride ceramics with built-in heating wires; the heater 54 is wrapped with a copper heat transfer block, and the sample to be tested 53 transfers heat through copper The block forms a closed loop with the first power interface 52-1 and the second power interface 52-2; the temperature measuring thermocouple 55 is arranged at one end of the copper heat transfer block that contacts the sample to be measured 53;

Further, the micro-probe base 4 is made of low thermal conductivity and heat-resistant insulating materials, such as zirconia ceramics, glass fiber composite materials, and polytetrafluoroethylene;

Further, the micro-probe 51 is made of tungsten.

In the test device provided by the present invention, the sample 53 to be tested is heated by alumina ceramics, aluminum nitride ceramics or silicon nitride ceramics with built-in heating wires, and the outer surface of the heater 54 is wrapped by a copper heat transfer block, so that the sample 53 to be tested is heated. A closed loop is formed with the first power interface 52-1 and the second power interface 52-2, and the heater 54 is powered by an external power source.

Further, a PID controller is also included, and the PID controller realizes precise temperature control of the heater 54 according to the temperature information collected by the temperature measuring thermocouple 55; the temperature control range of the heater 54 is from room temperature to 800°C, and the temperature control accuracy is preferably Within ±1℃.

In the test device provided by the present invention, the temperature information collected by the temperature measuring thermocouple 55 is fed back to the PID controller, and the temperature of the heater 54 is controlled by the PID controller.

Further, the image acquisition module 6 includes an optical imaging system for acquiring surface image information of the sample to be tested 53 ; the light source of the optical imaging system illuminates the sample to be tested 53 .

Further, an XYZ imaging fine-tuning module 7 for fine-tuning the focus of the optical imaging system is also included.

The test device provided by the present invention realizes the fine-tuning focusing of the optical imaging system through the XYZ imaging fine-tuning module 7, collects the surface image of the sample 53 to be tested, and performs image processing, so as to effectively realize the machine vision positioning. Compared with the existing device, a microscope is used for observation. , the operation is simpler, and the positioning accuracy is high.

Further, the resistance measurement unit includes a voltage-stabilized and constant-current power supply and a data acquisition module; the voltage-regulated and constant-current power supply is electrically connected to the first power supply interface 52-1 to supply power to the sample to be tested 53; the data acquisition module and the second power supply are electrically connected. The interface 52 - 2 is connected to the micrometer probe 51 for measuring the contact voltage between the sample to be tested 53 and the micrometer probe 51 .

Further, it also includes a computer unit for reading the surface image information of the sample to be tested 53 collected by the image acquisition module 6, reading the information of the data acquisition module, for setting the movement parameters of the displacement control unit, and controlling XYZ imaging. The focus of the fine-tuning module 7; the optical imaging system collects the surface image information of the sample to be tested 53 and inputs it into the computer, and positions the micro-probe 51 as the closed-loop correction information of the displacement control unit.

In the test device provided in this embodiment, the X displacement module 2, the Y displacement module 3 and the Z displacement module 1 include a stepper motor and a sliding table connected with its transmission. The computer unit can control the sliding table by adjusting the parameters of the stepper motor. The displacement of the stage is preferably controlled with an accuracy of less than 1 μm. In this embodiment, an industrial camera with auto-focus and more than 20 million pixels is used as the optical imaging system to collect the surface image of the sample to be tested 53 and input it into the computer, and perform closed-loop correction on the probe position information fed back by the displacement control unit, and finally correct the probe position. The positioning accuracy can reach below 0.5μm.

Further, the testing device provided by the present invention further includes a vacuum cover 8. During the test, a vacuum pump is used to evacuate the inside of the cover to a vacuum, and the vacuum degree of the vacuum is less than or equal to 10Pa.

The test method of applying the above-mentioned variable temperature heterogeneous interface contact resistivity test device includes the following steps:

Step ①, clamp the sample to be tested 53 in the temperature-variable clamping stand 5, and shake the hand wheel 57 to clamp the sample to be tested 53;

In step 2., the first power supply interface 52-1 is connected with a voltage-stabilized and constant-current power supply to provide a fixed current for the sample to be tested 53;

Step 3., set the heating temperature to the heater 54, and the temperature measuring thermocouple 55 collects the temperature of the heater 54 and feeds it back to the PID controller, and the precise temperature control of the heater 54 is controlled by the PID controller;

Step 4., connect the data acquisition module with the micrometer probe 51 and the second power supply interface 52-2, and set the scanning interval of the micrometer probe 51 on the surface of the sample to be tested 53 by the computer unit;

Step 5. Scan and measure, with the movement of the micrometer probe 51, the optical imaging system collects the surface image information of the sample to be tested 53 and inputs it into the computer, and positions the micrometer probe 51 as the closed-loop correction information of the displacement control unit, according to each scan Measure the corresponding voltage, and generate a graph of the relationship between the scanning path and the voltage value in the computer;

Step ⑥, according to the relationship between the scanning path and the voltage value and the fixed current value passing through the sample 53 to be tested, calculate the contact resistance R _c of the heterogeneous interface under temperature;

Step ⑦, adjust the heating temperature of the heater 54, and repeat the steps ③-⑥ to obtain the contact resistance of the heterogeneous interface under different temperature field conditions; combine the cross-sectional area size S of the sample 53 to be tested to calculate the contact resistance of the variable temperature heterogeneous interface resistivity.

Further, the calculation formula for calculating the contact resistivity of the temperature-changing interface is ρ _c =R _c ×S.

Example 2:

In this example, the test device and method in Example 1 are used to test the contact resistivity of the bismuth telluride material/Co interface of the sample. The sample is a bismuth telluride/Co/bismuth telluride sandwich structure, and the size is 3mm high*3mm* wide* Length 4mm, test temperature is room temperature 27℃, test current is 100mA DC, vacuum environment; test results are shown in Figure 4, the interface contact resistance is 0.12mΩ, and the interface contact resistance is calculated to be 10.8μΩcm ² .

Example 3:

In this example, the test device and method in Example 1 are used to test the contact resistivity of the skutterudite material/Mo interface of the sample. The sample is a Yb _0.3 Co ₄ Sb ₁₂ /Mo/Yb _0.3 Co ₄ Sb ₁₂ sandwich structure with a size of Height 2.52mm*width 2.77mm*length 4mm, the test temperature is 477°C, the test current is 100mA DC, and the vacuum environment; the test results are shown in Figure 5, the interface contact resistance value is 0.06mΩ, and the calculated interface contact resistance rate is 4.2 μΩcm ² .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structural transformation made by using the contents of the description and the accompanying drawings of the present invention, or directly or indirectly applied to other related technical fields, will not limit the scope of the invention. Similarly, it is included in the scope of patent protection of the present invention.

Claims (10)

1. A temperature-changing heterogeneous interface contact resistivity testing device is characterized by comprising:

the probe test platform is used for controlling the scanning of the micrometer probe on the surface of the sample to be tested; the method comprises the following steps: the micrometer probe seat is used for clamping the micrometer probe; the temperature-changing clamping rack is used for clamping and heating a sample to be tested; the image acquisition module is used for acquiring surface image information of the sample to be detected;

the displacement control unit is used for controlling the movement of the micrometer probe on the surface of the sample to be detected; comprises an X displacement module, a Y displacement module and a Z displacement module; the X displacement module and the Z displacement module are connected with the micrometer probe seat, and the Y displacement module is connected with the variable-temperature clamping rack;

and the resistance measuring unit is connected with the variable-temperature clamping rack and the micrometer probe.

2. The testing device of claim 1, wherein the temperature-changing holding rack comprises a first power interface, a second power interface, a heater for holding and heating a sample to be tested, and a temperature thermocouple; the temperature thermocouple is arranged at one end of the heater, which is contacted with the sample to be detected; the first power supply interface is electrically connected with the resistance testing unit and the sample to be tested to form a closed loop; the sample to be tested is arranged between the first power interface and the second power interface.

3. The testing device of claim 2, wherein the temperature-changing clamping rack further comprises a base, a bracket for fixing the heater and a hand-operated clamping mechanism for adjusting the clamping tightness of the sample to be tested; the bracket comprises a fixed bracket and a sliding bracket; the hand-operated clamping mechanism is arranged on the base and is connected with the sliding support.

4. The testing device of claim 3, wherein the hand-operated clamping mechanism comprises a hand-operated wheel and a slider; the sliding block is arranged on the base and is fixedly connected with the sliding support; the hand-operated wheel is in transmission connection with the sliding block.

5. The test apparatus according to claim 2, wherein the heater is selected from any one of alumina ceramic, aluminum nitride ceramic, and silicon nitride ceramic with a built-in heating wire; a copper heat transfer block is wrapped outside the heater, and the sample to be tested forms a closed loop with the first power interface and the second power interface through the copper heat transfer block; the temperature thermocouple is arranged at one end of the copper heat transfer block, which is contacted with the sample to be detected;

preferably, the micrometer probe seat is made of a low-thermal-conductivity heat-resistant insulating material;

preferably, the microprobe is made of tungsten.

6. The testing device of claim 2, further comprising a PID controller, wherein the PID controller realizes accurate temperature control of the heater according to the temperature information collected by the temperature thermocouple; the temperature control range of the heater is between room temperature and 800 ℃, and the temperature control precision is preferably within +/-1 ℃.

7. The testing device of claim 2, wherein the image acquisition module comprises an optical imaging system for acquiring surface image information of the sample to be tested; a light source of the optical imaging system irradiates the sample to be detected;

preferably, the image acquisition module further comprises an XYZ imaging fine adjustment module for fine adjustment focusing of the optical imaging system.

8. The testing device of claim 7, wherein the resistance measuring unit comprises a voltage-stabilizing and current-stabilizing power supply and a data acquisition module; the voltage-stabilizing and current-stabilizing power supply is electrically connected with the first power supply interface; and the data acquisition module is connected with the second power interface and the micrometer probe and is used for measuring the contact voltage of the sample to be measured and the micrometer probe.

9. The testing device of claim 8, further comprising a computer unit for reading the surface image information of the sample to be tested collected by the image collection module, reading the information of the data collection module, setting the movement parameters of the displacement control unit, and controlling the focusing of the XYZ imaging fine adjustment module; the optical imaging system collects surface image information of a sample to be measured, inputs the surface image information into a computer and positions the micrometer probe as closed loop correction information of the displacement control unit;

preferably, the movement accuracy of the displacement control unit is 1 μm or less;

preferably, the micrometer probe has a positioning accuracy of 0.5 μm or less.

10. The testing method of the temperature-changing hetero-interface contact resistivity testing device according to any one of claims 1 to 9, characterized by comprising the steps of:

(1) installing a sample to be detected in a variable-temperature clamping rack, and heating the sample to be detected;

(2) collecting a surface image of the sample to be detected, setting a scanning path and a scanning step length, and generating a micrometer probe target position;

(3) scanning measurement, wherein the micrometer probe performs resistance measurement once every step, a relation curve graph of a scanning path and a voltage value is drawn, and the contact resistance R of the heterogeneous interface at the heating temperature is obtained through calculation_cAccording to the geometric parameters of the sample to be measured, and the contact resistance R_cAnd calculating to obtain the contact resistivity rho of the heterogeneous interface at the heating temperature_c。

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