Wafer resistivity detection method, device, electronic device and storage medium

Abstract

The present application discloses a method, device, electronic device, and storage medium for detecting wafer resistivity. The method includes: fixing a test sample on a test platform so that the test sample can reciprocate in a preset direction driven by the test platform; when the test sample moves below a sampling unit, controlling the test sample to move in a first preset direction so that the sampling unit samples sampling points on the test sample at intervals; controlling the test sample to rotate about its axis by a set angle and controlling the test sample to move relative to the sampling unit in a second preset direction so that the sampling unit samples sampling points on the test sample at intervals, the second preset direction being opposite to the first preset direction; determining a reference voltage at the sampling point based on the difference between the detection voltage and the no-load voltage at the sampling point; and substituting the reference voltage into a pre-established resistivity calculation formula to obtain the resistivity. This method has higher efficiency and higher accuracy in detecting wafer resistivity.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor performance parameter detection methods, and in particular to a wafer resistivity detection method, device, electronic equipment, and storage medium. Background Art

[0002] Silicon carbide (SiC) wafers, as an important semiconductor material, are widely used in electronic devices operating in extreme environments such as high power, high frequency, and high temperature. During the production and manufacturing process of SiC wafers, wafer stability plays a crucial role in their operating efficiency. To ensure the quality and performance of SiC wafers, resistivity has become a key quality inspection indicator during the SiC wafer production process. The resistivity parameter not only directly affects the electrical properties of SiC wafers but also determines their overall performance, such as conductivity, voltage resistance, and reliability when used in power devices.

[0003] However, existing resistivity testing methods for silicon carbide wafers have certain limitations. Existing resistivity testing devices generally have problems such as low detection efficiency and a small number of collection points. They can usually only perform a single test in a single direction on the test sample, which leads to poor representativeness of the test results and an inability to fully reflect the electrical properties of the silicon carbide wafer. In addition, since the existing equipment has a long substrate transport time when performing resistivity testing, each placement and adjustment process of the test sample requires additional time, which is not continuous and efficient enough. The overall detection cycle is slow, which affects the efficiency of the production line and cannot meet the needs of high-speed production and large-scale testing. Summary of the Invention

[0004] In order to address the deficiencies of the prior art, the purpose of this application is to provide a method, device, electronic device and storage medium for detecting wafer resistivity with high detection efficiency and high detection accuracy.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for detecting wafer resistivity, the method comprising:

[0007] Fix the sample to be tested on the testing platform so that the sample to be tested can reciprocate along the preset direction under the drive of the testing platform;

[0008] When the sample to be tested moves to below the sampling unit, the sample to be tested is controlled to move relative to the sampling unit along a first preset direction, so that the sampling unit samples a plurality of first sampling points on the sample to be tested at intervals to determine a detection voltage at each first sampling point;

[0009] Controlling the test sample to rotate around its axis by a set angle, controlling the test sample to move relative to the sampling unit along a second preset direction, so that the sampling unit samples a plurality of second sampling points on the test sample at intervals to determine a detection voltage at each second sampling point, wherein the second preset direction is opposite to the first preset direction;

[0010] In the case of determining the no-load voltage of the sampling unit, determining the reference voltage of each sampling point based on the difference between the detection voltage and the no-load voltage at each sampling point;

[0011] Based on a pre-established resistivity calculation formula, the reference voltage of each sampling point is substituted into the resistivity calculation formula to obtain the resistivity of each sampling point.

[0012] Furthermore, the method further comprises:

[0013] The number of sampling points can be increased or decreased by increasing or decreasing the number of rotations of the sample to be tested.

[0014] Furthermore, in the process of determining the detection voltage of each first sampling point, the method includes: determining a position of a first sampling point so that a sampling unit samples first initial voltages on both sides of the first sampling point at intervals; determining an average value of the first initial voltages as the detection voltage of the first sampling point;

[0015] The process of determining the detection voltage of each second sampling point includes: determining the position of a second sampling point so that the sampling unit samples the second initial voltages on both sides of the second sampling point at intervals; and determining the average value of the plurality of second initial voltages as the detection voltage of the second sampling point.

[0016] Furthermore, in the process of the sampling unit intermittently sampling the first initial voltage on both sides of a first sampling point, the process includes: when a first sampling point approaches the sampling unit along a first preset direction, if the first sampling point reaches a first preset distance from the sampling unit, the sampling unit starts to intermittently sample the first initial voltage; when a first sampling point moves away from the sampling unit along the first preset direction, if the first sampling point reaches a second preset distance from the sampling unit, the sampling unit stops sampling the first initial voltage, and the first preset distance is equal to the second preset distance.

[0017] Furthermore, in the process of determining the pre-established resistivity calculation formula, the process includes: obtaining two calibration samples with the highest resistivity and the lowest resistivity from the sample library; and obtaining a first fixed coefficient and a second fixed coefficient in the resistivity calculation formula by determining the reference voltage, thickness, and resistivity of each of the two calibration samples. The resistivity calculation formula satisfies the following relationship: ; Wherein, R represents resistivity, K represents the first fixed coefficient, T represents thickness, V represents reference voltage, and B represents the second fixed coefficient.

[0018] Furthermore, the method further includes: determining a resistivity interval of the two calibration samples; and when determining the resistivity of each sampling point, replacing the calibration sample if the resistivity of the sampling point is outside the resistivity interval.

[0019] Furthermore, in the process of controlling the sample to be tested to rotate around its axis to a set angle, it includes: lifting the sample to be tested upward by an adjustment unit arranged under the detection platform, so that the sample to be tested leaves the detection platform; the adjustment unit rotates around the axis of the sample to be tested to drive the sample to be tested to rotate the set angle; and placing the sample to be tested after rotating the set angle on the adjustment platform.

[0020] In a second aspect, the present application further provides a device for detecting wafer resistivity, the device comprising:

[0021] The testing platform is used to carry the sample to be tested, so that the sample to be tested can reciprocate along the preset direction under the drive of the testing platform;

[0022] An adjustment unit is used to control the sample to be tested to rotate around its own axis to a set angle;

[0023] The sampling unit is configured to sample a plurality of first sampling points on a test sample at intervals. When the test sample moves below the sampling unit, the test sample can move relative to the sampling unit in a first preset direction to determine a detection voltage at each first sampling point. After the test sample is controlled to rotate by a set angle by an adjustment device, the test sample can move relative to the sampling unit in a second preset direction, so that the sampling unit samples a plurality of second sampling points on the test sample at intervals to determine a detection voltage at each second sampling point. The second preset direction is opposite to the first preset direction.

[0024] The control module is configured to determine a reference voltage at each sampling point based on the difference between the detection voltage and the no-load voltage at each sampling point when the no-load voltage of the sampling unit is determined; and substitute the reference voltage at each sampling point into the resistivity calculation formula based on a pre-established resistivity calculation formula to obtain the resistivity of each sampling point.

[0025] In a third aspect, the present application further provides an electronic device, comprising:

[0026] A memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of any one of the sample resistivity detection methods of the first aspect are implemented.

[0027] In a fourth aspect, the present application further provides a computer-readable storage medium, in which computer-executable instructions are stored. The computer-executable instructions are used to enable a computer to execute any one of the sample resistivity detection methods of the first aspect.

[0028] The wafer resistivity detection method provided in this application drives the test sample to reciprocate relative to a sampling unit and controls the rotation of the test sample after each lateral movement in one direction to adjust the test sample's angle. This optimizes the detection path, improves detection efficiency, and effectively reduces the deviation of unidirectional sampling. This detection method can obtain a larger number of sampling points in a complete sampling operation, improving the accuracy and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of the resistivity detection method in the embodiment of the present application;

[0030] Figure 2 This is a schematic structural diagram of a resistivity detection device in an embodiment of the present application;

[0031] Figure 3 This is a schematic diagram of several sampling points in an embodiment of the present application;

[0032] Figure 4 This is a flow chart of the acquisition unit acquiring the initial voltages on both sides of the first sampling point in an embodiment of the present application;

[0033] Figure 5 Flowchart for determining pre-established resistivity calculation formula;

[0034] Figure 6 This is a flow chart of determining a resistivity interval in a resistivity detection method in an embodiment of the present application;

[0035] Figure 7 This is a flow chart of controlling the rotation of the sample to be tested around its axis to set an angle in an embodiment of the present application;

[0036] Figure 8 This is a structural schematic diagram of a resistivity detection device according to another angle in an embodiment of the present application;

[0037] Figure 9 This is a diagram of the internal structure of an electronic device in an embodiment of the present application.

[0038] Figure numerals: 100, resistivity detection device; 10, detection platform; 11, silicon carbide base plate; 12, screw module; 13, connecting plate; 20, adjustment unit; 21, cylinder; 22, ceramic suction cup; 221, vacuum chamber; 23, rotation drive assembly; 30, sampling unit; 31, resistivity probe. DETAILED DESCRIPTION

[0039] In order to make those skilled in the art better understand the present application, the following will be combined with the accompanying drawings in the present application to clearly and completely describe the technical solutions in the specific embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0040] It should be noted that the directional nouns such as up, down, left, right, front, and back, or ordinal numbers such as "first, second, third, and fourth" mentioned in this document are based on the drawings in the specification and are introduced for the convenience of description. They do not mean any limitation on the order of the components. In addition, since the functions of certain parts of the various components provided in the above embodiments are the same, this specification adopts a unified naming method for these parts. The above is a detailed introduction to the pipe fitting connection device provided by the relevant technical solution, and specific embodiments are used in this article for elaboration. The description of the above embodiments is only used to help understand the method and core concept of the present invention, and does not impose any form of limitation on the present invention.

[0041] like Figure 2 As shown, the present application provides a resistivity detection device 100. In order to clearly illustrate the technical solution of the present invention, the following is also defined: Figure 2 The up-down, left-right, and front-back directions shown are the up-down, left-right, and front-back directions of the resistivity detection device 100. In the description of this application, the width direction of the resistivity detection device 100 is Figure 2 The front-to-back direction is shown, and the height direction of the resistivity detection device 100 is Figure 1 The vertical direction shown is the longitudinal direction of the resistivity detection device 100. Figure 1 Left and right directions shown.

[0042] like Figure 1 As shown, the present application provides a method for detecting wafer resistivity, comprising the following steps:

[0043] Step S101 : Fix the sample to be tested on the testing platform 10 so that the sample to be tested can reciprocate along a preset direction under the drive of the testing platform 10 .

[0044] like Figure 2As shown, exemplarily, the sample to be tested is set to at least one of the two types of silicon carbide wafers, 6 inches / 8 inches, and the detection platform 10 includes a silicon carbide base plate 11, a screw module 12, and a connecting plate 13. The sample to be tested is placed on the silicon carbide base plate 11, and the screw module 12 is connected to the connecting plate 13. The screw module 12 is used to drive the detection platform 10 to reciprocate along a preset direction. The connecting plate 13 fixes the screw module 12 and the silicon carbide base plate 11 to ensure the stability of the reciprocating motion of the screw module 12. The detection platform 10 drives the sample to be tested to reciprocate through the reciprocating motion of the screw module 12, thereby enabling the sample to be tested to reciprocate along the preset direction.

[0045] Step S102 : When the sample to be tested moves to below the sampling unit 30 , the sample to be tested is controlled to move relative to the sampling unit 30 along a first preset direction, so that the sampling unit 30 samples a plurality of first sampling points on the sample to be tested at intervals to determine the detection voltage of each first sampling point.

[0046] like Figure 2 As shown, the sampling unit 30 is illustratively used to sample the test voltage of the test sample. The sampling unit 30 includes a resistivity probe 31 and a positioning sensor (not shown). At least a portion of the resistivity probe 31 is located above the silicon carbide base plate 11. The resistivity probe 31 is used to implement the sampling function of the sampling unit 30. The positioning sensor is used to detect the displacement distance of the lead screw module 12. This displacement distance can represent the distance the sampling unit 30 approaches or moves away from a plurality of first sampling points on the test sample in a first preset direction. This displacement distance is used to determine when the sampling unit 30 starts or stops testing, enabling the resistivity probe 31 to accurately locate the spacing between the plurality of first sampling points. It should be noted that the first preset direction refers to the direction of movement of the test sample on the testing platform 10. By controlling the testing platform 10 to move in the first preset direction, the test sample is moved in the first preset direction. Sampling by the sampling unit 30 is performed at intervals, and the intervals are preset by software.

[0047] For example, when sampling one of the first sampling points, the sampling unit 30 begins testing when the sample moves to a position 1 mm from the first sampling point. When the sample moves to a position 1 mm from the first sampling point, the sampling unit 30 stops testing. The sampling density of the sampling points follows the principle of uniform distribution. For example, 20 sampling points are formed between a position 1 mm from the first sampling point and a position 1 mm from the first sampling point. After the sampling unit 30 detects 20 voltage data points, the average value is calculated and used as the detection voltage at the first sampling point.

[0048] Step S103: Control the sample to be tested to rotate around its axis by a set angle, and control the sample to be tested to move relative to the sampling unit 30 along a second preset direction, so that the sampling unit 30 samples a plurality of second sampling points on the sample to be tested at intervals to determine the detection voltage of each second sampling point, and the second preset direction is opposite to the first preset direction.

[0049] like Figure 2 As shown, for example, the adjustment unit 20 is used to control the rotation of the sample to be tested around its axis to a set angle. The adjustment unit 20 includes a cylinder 21, a ceramic suction cup 22, and a rotation drive assembly 23. The cylinder 21 is fixed below the detection platform 10. The silicon carbide base plate 11 is provided with a receiving space 111 for the ceramic suction cup 22 to pass vertically. The ceramic suction cup 22 is arranged in the receiving space 111. The piston rod of the cylinder 21 can vertically lift the ceramic suction cup 22 to separate the sample to be tested from the silicon carbide base plate 11. A plurality of vacuum chambers 221 are provided in the ceramic suction cup 22. By extracting the air in the vacuum chamber 111, a negative pressure is formed in the vacuum chamber 221. Under the action of atmospheric pressure, the sample to be tested is adsorbed on the ceramic suction cup 22 by vacuum adsorption, thereby fixing the sample to be tested. The ceramic suction cup 22 is driven by the rotation drive assembly 23 to rotate around its own axis to a set angle. The rotation drive assembly 23 is provided with an encoder. The encoder is used to feedback the preset rotation angle, thereby achieving precise control of the angle of each rotation.

[0050] like Figure 3 As shown, after the sampling unit 30 completes sampling of the sample to be tested along the first preset direction, the rotation drive assembly 23 drives the sample to be tested to rotate by a set angle (e.g., 15°) to prepare for the next round of voltage sampling. When the sample to be tested completes its rotation, the detection platform 10 controls the sample to move smoothly along a second preset direction (the second preset direction is opposite to the first preset direction), wherein: Figure 3 The numbers in the figure represent the sampling path. The sample to be tested is inspected by rotating the test path in a unidirectional reciprocating motion. This method ensures that after each rotation, the sampling unit 30 can measure the voltage at the newly located sampling point in the shortest possible time. This arrangement allows the sampling unit 30 to achieve higher sampling efficiency per unit sampling time.

[0051] Step S104 : when the no-load voltage of the sampling unit 30 is determined, a reference voltage of each sampling point is determined based on the difference between the detection voltage and the no-load voltage at each sampling point.

[0052] Specifically, the no-load voltage refers to the voltage value obtained by the sampling unit 30 measuring the air when the sampling unit 30 is not sampling the sample to be tested. The no-load voltage needs to be calibrated before each test, and the ambient temperature is controlled at 25°C±1°C and the humidity is ≤50% to eliminate environmental interference. The measurement of the no-load voltage is to ensure the basic voltage state of the sampling unit 30 when there is no external influence. In this process, the no-load voltage is directly read by the resistivity probe without contacting the sample to be tested. The calculation formula of the reference voltage is ;in, is the reference voltage of the sampling point, is the detection voltage at the sampling point, is the no-load voltage at the sampling point.

[0053] Step S105: Based on a pre-established resistivity calculation formula, the reference voltage of each sampling point is substituted into the resistivity calculation formula to obtain the resistivity of each sampling point.

[0054] Specifically, before the actual test, the resistivity and thickness of the two silicon wafers with the highest and lowest resistivity are measured in the sample library as known conditions. These two silicon wafers are used as calibration samples. The calibration method is to move the center position of the calibration sample to the bottom of the sampling unit 30 and start collecting voltage. , the detection voltage of the calibration sample minus the no-load voltage is the required reference voltage. It should be noted that the no-load voltage is the output voltage when the sampling unit 30 is not in contact with the sample to be tested, and the detection voltage is the output voltage when the sampling unit 30 samples the sample to be tested. After the two calibration samples are calibrated, the value of the first fixed coefficient K is obtained, and then the value of the second fixed coefficient B is calculated using the obtained value of the first fixed coefficient K, and then the values ​​of the first fixed coefficient K and the second fixed coefficient B are obtained. The resistivity calculation formula involves the thickness of the sample to be tested, the voltage difference and the resistivity coefficient of the material. The reference voltage of the sampling point of the sample to be tested is substituted into the resistivity calculation formula Where R represents the resistivity to be determined, K represents the first fixed coefficient, calculated based on the calibration sample data, T represents the thickness of the test sample, V represents the reference voltage, calculated by dividing the voltage difference at each sampling point by the no-load voltage, and B represents the second fixed coefficient, calculated based on the calibration sample data. Once the first fixed coefficient K, the second fixed coefficient B, and the thickness T of the test sample are determined, the reference voltage V of the test sample is substituted to determine the resistivity at each sampling point.

[0055] In the embodiment of the present application, the detection method drives the test sample to reciprocate relative to the sampling unit 30 and controls the rotation of the test sample after each lateral movement in one direction to adjust the angle of the test sample. This optimizes the detection path, improves detection efficiency, and effectively reduces the deviation of unidirectional sampling. The combination of rotation and movement effectively increases the coverage of the detection path, ensuring that the resistivity of each area of ​​the test sample can be fully detected. Based on this detection method, a larger number of sampling points can be obtained in a complete sampling process, improving the accuracy and reliability of the measurement results.

[0056] As an implementation method, the number of sampling points can be increased or decreased by increasing or decreasing the number of rotations of the sample to be tested.

[0057] Specifically, by changing the number of rotations of the sample to be tested, the sampling unit 30 will sample voltage at certain intervals on the surface of the sample as it rotates. Each change in the rotation angle will result in a change in the distribution of the sampling points. By adjusting the rotation angle, the number of sampling points can be increased or decreased. For example, if the rotation is 15° each time, the sampling unit 30 will collect new sampling points on the sample after each rotation. If the rotation angle is reduced to 10°, the number of samples taken each time increases because more sampling points can be captured within the same rotation range. Conversely, if the rotation angle is increased to 30°, the number of samples taken each time decreases, saving detection time. By reducing the number of rotations, the speed of the production line can be effectively increased while still ensuring the required basic detection effect.

[0058] In the embodiments of this application, by increasing or decreasing the number of rotations of the test sample, the number of sampling points can be flexibly controlled, achieving adaptability and adjustability of the detection method. This configuration enhances the flexibility of the resistivity detection method, allowing the number of sampling points to be adjusted according to different detection requirements, thereby optimizing the balance between detection accuracy and detection efficiency during the resistivity detection process.

[0059] As an implementation, the process of determining the detection voltage at each first sampling point includes: determining a position of a first sampling point so that the sampling unit 30 samples first initial voltages on both sides of the first sampling point at intervals; determining an average value of the first initial voltages as the detection voltage at the first sampling point;

[0060] The process of determining the detection voltage of each second sampling point includes: determining the position of a second sampling point so that the sampling unit 30 samples the second initial voltages on both sides of the second sampling point at intervals; and determining the average value of the plurality of second initial voltages as the detection voltage of the second sampling point.

[0061] Specifically, in the process of determining the detection voltage of each sampling point, the sampling unit 30 samples the voltages on both sides of each sampling point and takes the average value as the final detection voltage. Simple single-point sampling may lead to inaccurate measurements due to the surrounding environment or equipment errors. For example, factors such as slight deviations of the equipment and uneven surface of the sample to be tested may cause the measured value of a single sampling point to be too high or too low. By collecting data at multiple locations of the sampling point at intervals and calculating the average value, local unevenness and errors will be smoothed, making the final measured voltage value more accurate and realistic. At the same time, this method can obtain data from a wider range of areas, so that the detection voltage of each sampling point not only reflects a certain local situation, but reflects the overall electrical properties of the area near the point. By sampling the voltages on both sides of each sampling point and taking the average value, local errors can be eliminated, making the detection voltage of each sampling point more representative and reliable.

[0062] In an embodiment of the present application, a method for accurately sampling the voltage at a sampling point on a sample to be tested is provided. This method samples the voltage on both sides of each sampling point and takes the average value as the final test voltage. Averaging the multiple voltage values ​​measured on both sides of the sampling point can reduce the effects of single-measurement errors or localized inhomogeneities, thereby improving the accuracy of the test voltage measurement, reducing local errors, and enhancing the representativeness and reliability of the sampling points, thereby ensuring the accuracy of the test voltage measurement.

[0063] like Figure 4 As shown, as an implementation manner, in the process of the sampling unit 30 sampling the first initial voltages on both sides of a first sampling point at intervals, the following steps are included:

[0064] Step S301 : When a first sampling point approaches the sampling unit 30 along a first preset direction, if the first sampling point reaches a first preset distance from the sampling unit 30 , the sampling unit 30 starts to collect a first initial voltage at intervals.

[0065] Specifically, the first preset distance refers to the specific distance between the sampling unit 30 and the point where sampling begins when the sample approaches the sampling unit 30 along the first preset direction. The sampling unit 30 begins sampling when the distance between the sampling point of the sample approaches the sampling unit 30 and reaches the first preset distance. For example, the PLC control system monitors the actual position of the motion mechanism and begins sampling when the sampling point of the sample moves to a position 1 mm from the sampling unit 30.

[0066] Step S302 : When a first sampling point moves away from the sampling unit 30 along the first preset direction, if the first sampling point reaches a second preset distance from the sampling unit 30 , the sampling unit 30 stops collecting the first initial voltage, and the first preset distance is equal to the second preset distance.

[0067] Specifically, the second preset distance refers to the specific distance between the sampling unit 30 and the point where sampling begins on the sample to be tested, when the sample to be tested moves away from the sampling unit 30 along the first preset direction. When the distance between the sampling point on the sample to be tested and the sampling point reaches the second preset distance, the sampling unit 30 stops sampling. For example, the PLC control system monitors the actual position of the motion mechanism and terminates sampling when the sampling point on the sample to be tested moves to a position 1 mm away from the sampling unit 30. The first preset distance and the second preset distance are equal, indicating that the sampling unit 30 has the same starting and stopping distance range for sampling.

[0068] In the embodiments of the present application, the distance between the sample to be tested and the sampling unit 30 is controlled to precisely control the start and end timing of sampling, avoiding redundant sampling of irrelevant areas, reducing sampling waste, and improving the accuracy of the sampled data. The first preset distance is equal to the second preset distance, ensuring that the sampling range on both sides of the sampling unit 30 remains consistent during the sampling process. This reduces measurement errors in the voltage data at each sampling point, providing more accurate sampling data and further improving the reliability of the resistivity measurement results.

[0069] like Figure 5 As shown, as an implementation method, in the process of determining the pre-established resistivity calculation formula, the following steps are included:

[0070] Step S401: obtaining two calibration samples with the largest resistivity and the smallest resistivity from a sample library;

[0071] Specifically, the sample library is a collection of calibration samples with known resistivity, thickness, and voltage characteristics. Each calibration sample has been carefully tested, and its electrical and physical properties (such as resistivity, thickness, and reference voltage) have been measured and recorded. Calibration samples are used to calibrate resistivity measurement methods and equipment. The sample library provides a standardized benchmark, ensuring the accuracy of resistivity measurement methods. By selecting the calibration sample with the highest resistivity as calibration sample one and the calibration sample with the lowest resistivity as calibration sample two, test results covering the entire resistivity range can be obtained for the samples to be tested.

[0072] Step S402: After determining the reference voltage, thickness, and resistivity of the two calibration samples, obtain a first fixed coefficient and a second fixed coefficient in a resistivity calculation formula;

[0073] Specifically, the resistivity calculation formula satisfies the following relationship: Using the known data from the calibration sample, the first fixed coefficient K and the second fixed coefficient B can be inferred from the known resistivity calculation formula. The resistivity (R1 and R2), thickness (T1 and T2), and reference voltage (V1 and V2) of the calibration sample are all known quantities. Therefore, by substituting these known data, the first fixed coefficient K and the second fixed coefficient B can be calculated. The first fixed coefficient K and the second fixed coefficient B will be used as constants in the subsequent resistivity calculation to ensure the accuracy of the formula. Given the reference voltage, thickness, and resistivity of the two calibration samples, substitute the basic calculation formula:

[0074]

[0075]

[0076] Among them, V1 is the reference voltage of calibration sample one; V2 is the reference voltage of calibration sample two; the reference voltage is the difference between the detection voltage and the no-load voltage; T1 is the thickness of calibration sample one; T2 is the thickness of calibration sample two; R1 is the resistivity of calibration sample one; R2 is the resistivity of calibration sample two; the first fixed coefficient K and the second fixed coefficient B are values ​​to be determined.

[0077] Calculation of the first fixed coefficient K:

[0078]

[0079] Calculation of the second fixed coefficient B:

[0080]

[0081] The specific values ​​of the first fixed coefficient and the second fixed coefficient can be calculated using the known voltage, thickness, and resistivity data of the calibration sample. For example, the thickness of calibration sample 1 is T1 = 336.5 μm, the resistivity of calibration sample 1 is R1 = 0.3238 Ω·cm, and the reference voltage of calibration sample 1 is V1 = 8.712 V. The thickness of calibration sample 2 is T2 = 300.6 μm, the resistivity of calibration sample 2 is R2 = 1.1960 Ω·cm, and the reference voltage of calibration sample 2 is V2 = 2.039 V.

[0082] The first fixed coefficient K = (8.712-2.039) / (336.5 / 0.3238-300.6 / 1.1960) = 0.00846952;

[0083] The second fixed coefficient B=8.712-0.00846952*336.5 / 0.3238= 0.08971082;

[0084] Step S403: The resistivity calculation formula satisfies the following relationship: ; Wherein, R represents resistivity, K represents the first fixed coefficient, T represents thickness, V represents reference voltage, and B represents the second fixed coefficient.

[0085] Specifically, the resistivity calculation formula satisfies the following relationship: ; Wherein, the values ​​of the first fixed coefficient K and the second fixed coefficient B can be obtained through the above-mentioned step S402, which will not be repeated here. T is the thickness of the sample to be tested, V represents the reference voltage of the sample to be tested, and the thickness T of the sample to be tested is obtained by directly measuring the sample to be tested with a mechanical measuring instrument, such as using a micrometer or a caliper for direct measurement. This method determines the thickness by directly contacting the upper and lower surfaces of the sample to be tested, and is suitable for most samples to be tested of standard thickness. V is the reference voltage of the sample to be tested, and the detection is carried out with reference to the methods provided in other embodiments of this application, which will not be repeated here. By substituting the first fixed coefficient K, the second fixed coefficient B, the thickness T of the sample to be tested, and the reference voltage V into the resistivity calculation formula, the resistivity R of the sample to be tested can be obtained.

[0086] For example, the thickness of the sample to be tested is T = 298.9μm, and the measured reference voltage is V = 3.927V. Calculate the resistivity R.

[0087] Resistivity R=K*T / (VB)= 0.00846952*298.9 / (3.927-0.08971082)=0.6597Ω·cm.

[0088] In an embodiment of the present application, the first fixed coefficient K and the second fixed coefficient B in the resistivity calculation formula are calculated by using calibration samples with the maximum resistivity and the minimum resistivity, thereby ensuring that the resistivity calculation formula can adapt to test samples of different thicknesses and resistivity ranges, reducing errors caused by equipment differences, environmental changes or calibration sample differences, and thus obtaining reliable measurement results within different resistivity ranges, improving measurement accuracy, and improving the accuracy of the resistivity R of the test sample.

[0089] like Figure 6 As shown, as an implementation method, the resistivity detection method of the sample to be tested further includes the following steps:

[0090] Step S501: determining the resistivity range of two calibration samples;

[0091] Specifically, by selecting the calibration samples with the minimum resistivity and the maximum resistivity, an interval covering the resistivity range of the sample to be tested can be determined. This interval is the resistivity interval, which represents the effective range or normal variation range of the resistivity. For the sample to be tested within the resistivity interval, the resistivity value calculated by the resistivity calculation formula will be reasonable and accurate. By setting the resistivity interval, it is possible to avoid inaccurate measurements of the resistivity calculation formula on the sample to be tested whose resistivity is outside the limit value. The setting of the resistivity interval enables the resistivity calculation formula to adapt to the resistivity in the common range without deviating from the actual material properties. For example, after actual testing, the reference voltages of calibration sample one and calibration sample two are detected, and the respective resistivities are determined by the method in the above embodiment to determine the resistivity interval of the two calibration samples.

[0092] Step S502: When the resistivity of each sampling point is determined, if the resistivity of the sampling point is outside the resistivity range, the calibration sample is replaced.

[0093] Specifically, if the resistivity of the test sample exceeds the resistivity range, the test sample is replaced with a new calibration sample. For example, if the measured resistivity of the test sample is higher than the resistivity of the calibration sample with the highest resistivity, the new calibration sample is selected and added to the sample library. The resistivity of the new calibration sample can cover the new measurement range, thereby ensuring measurement accuracy and consistency.

[0094] In the embodiment of the present application, by introducing the resistivity interval and the mechanism of replacing the calibration sample, it is possible to ensure that the resistivity calculation formula can always maintain high accuracy within different resistivity ranges, thereby improving the accuracy of resistivity detection.

[0095] like Figure 7 As shown, as an implementation method, in the process of controlling the sample to be tested to rotate around its axis at a set angle, the following steps are included:

[0096] Step S601: The adjustment unit 20 provided below the detection platform 10 is used to lift the sample to be tested upward, so that the sample to be tested leaves the detection platform 10;

[0097] Specifically, a ceramic suction cup is fixed to the top of the piston rod of the cylinder and is used to absorb and fix the sample to be tested. When the sample needs to be rotated, the cylinder is activated, and the piston rod lifts the ceramic suction cup and the sample to be tested upward, so that they are separated from the detection platform 10, thereby eliminating the contact friction between the sample to be tested and the detection platform 10. The cylinder provides power through the pneumatic system, so that the sample to be tested leaves the ceramic suction cup, providing space for subsequent rotation and position adjustment. The lifting action is controlled by the PLC control system, and the trigger signal comes from the motion position feedback of the detection platform 10.

[0098] Step S602: the adjusting unit 20 rotates around the axis of the sample to be tested to drive the sample to be tested to rotate a set angle;

[0099] Specifically, the rotation drive assembly of adjustment unit 20 also includes a first motor and a rotary bearing. The first motor is connected to the ceramic chuck. Once the sample is lifted, the first motor drives the ceramic chuck and the sample to be tested to rotate around its central axis by a set angle (for example, 15°). The rotation angle is fed back in real time by an encoder, with an accuracy of ±0.1°. During rotation, the ceramic chuck maintains vacuum to prevent the sample from shifting.

[0100] Step S603: placing the sample to be tested after being rotated to a set angle on the adjustment platform.

[0101] Specifically, after the rotation is complete, the cylinder piston rod slowly descends, repositioning the ceramic chuck and the test sample onto the silicon carbide baseplate. The ceramic chuck releases its vacuum, and the test sample is slightly secured by the elastic deformation of the silicon carbide baseplate. The screw module then activates, driving the test sample in a second predetermined direction.

[0102] In this embodiment, the adjusting unit 20 is provided to achieve accurate rotation of the sample to be tested, so that the detection range of the sampling unit 30 can better cover different parts of the sample to be tested.

[0103] Based on the same inventive concept, embodiments of the present application also provide a wafer resistivity detection device for implementing the aforementioned wafer resistivity detection method. The implementation solution provided by the resistivity detection device 100 is similar to the implementation solution described in the aforementioned method. Therefore, the specific limitations of one or more wafer resistivity detection device embodiments provided below can be found in the limitations of the wafer resistivity detection method described above and will not be repeated here.

[0104] like Figure 8 As shown, as an implementation method, the present application provides a wafer resistivity detection device, the resistivity detection device 100 includes: a detection platform 10, an adjustment unit 20, a sampling unit 30, and a control module, wherein:

[0105] The testing platform 10 is used to carry the sample to be tested, so that the sample to be tested can reciprocate along a preset direction under the drive of the testing platform 10;

[0106] The adjustment unit 20 is used to control the sample to be tested to rotate around its own axis to a set angle;

[0107] The sampling unit 30 is used to sample a plurality of first sampling points on the test sample at intervals. When the test sample moves below the sampling unit 30, the test sample can move relative to the sampling unit 30 in a first preset direction to determine the detection voltage of each first sampling point. After the test sample is controlled to rotate by a set angle by the adjustment device, the test sample can move relative to the sampling unit 30 in a second preset direction, so that the sampling unit 30 samples a plurality of second sampling points on the test sample at intervals to determine the detection voltage of each second sampling point. The second preset direction is opposite to the first preset direction.

[0108] The control module is configured to determine a reference voltage at each sampling point based on a difference between the detection voltage at each sampling point and the no-load voltage when the no-load voltage of the sampling unit 30 is determined; and to substitute the reference voltage at each sampling point into a resistivity calculation formula based on a pre-established resistivity calculation formula to obtain the resistivity at each sampling point.

[0109] like Figure 8 As shown, as an implementation method, the detection platform 10 is used to carry the sample to be tested and ensure that the sample can reciprocate along a preset direction during the detection process.

[0110] During the testing process, the testing platform 10, driven by the screw module 12, moves the test sample along a first predetermined direction to below the sampling unit 30. At this point, the sampling unit 30 collects voltage at the first sampling point. After the collection is complete, the adjustment unit 20 is activated to lift the test sample and rotate it by a set angle (e.g., 15°), then reposition it on the testing platform 10. At this point, the testing platform 10 moves along a second predetermined direction, and the sampling unit 30 collects voltage at the second sampling point.

[0111] In the embodiment of the present application, the detection platform 10 is driven by the screw module 12 so that the sample to be tested performs a linear reciprocating motion along a preset direction on the detection platform 10, which significantly improves the detection efficiency.

[0112] Furthermore, the adjustment unit 20 is used to control the rotation of the test sample around its axis to a set angle. During operation of the adjustment unit 20, the cylinder 21 first lifts the ceramic suction cup 22 and the test sample, separating them from the test platform 10. Subsequently, the first motor drives the ceramic suction cup 22 and the test sample to rotate around the central axis to a set angle. After the rotation is completed, the cylinder 21 descends, repositioning the test sample on the silicon carbide base plate 11. At this time, the test platform 10 moves along the second preset direction, and the sampling unit 30 collects voltage at the second sampling point.

[0113] In the embodiment of the present application, precise rotation of the adjustment unit 20 is achieved through the structural coordination of various parts of the adjustment unit 20, laying a foundation for multi-angle and multi-directional detection of the sample to be tested.

[0114] Furthermore, the sampling unit 30 is used to periodically sample a plurality of first and second sampling points on the test sample. During the sampling process, when the test platform 10 moves the test sample below the resistivity probe 31, the control module instructs the sampling unit to start voltage acquisition at a distance of 1 mm from the sampling point and to stop acquisition after the distance exceeds 1 mm. Twenty sets of voltage data are collected at each sampling point, and the control module calculates the average value as the test voltage, subtracting the no-load voltage (the output voltage of the resistivity probe when it is suspended) in real time.

[0115] In the embodiments of the present application, bidirectional sampling of the sample to be tested is achieved through precise control of the control module. The voltage sampling in this embodiment improves measurement accuracy through the averaging method, solving the problem of a small number of sampling points and low detection efficiency in the prior art, and achieving multi-point sampling and high-precision detection.

[0116] Furthermore, the control module includes a host computer and a PLC control system. The host computer is used to receive and process the voltage data collected by the sampling unit 30, and the PLC control system is used to control the actions of the detection platform 10, the adjustment unit 20 and the sampling unit 30. The PLC control system uploads the collected voltage data to the host computer, and the host computer has a built-in calibration algorithm module for determining the reference voltage of each sampling point based on the difference between the detection voltage and the no-load voltage of each sampling point when the no-load voltage of the sampling unit 30 is determined. Using the pre-established resistivity calculation formula, the reference voltage of each sampling point is substituted into the formula to calculate the resistivity of each sampling point. If the resistivity of the sample to be tested exceeds the preset range, the host computer prompts to update the sample library, and recalculates the K and B values ​​by adding a calibration sample to ensure detection accuracy.

[0117] In the embodiments of the present application, the automatic calculation function of the control module solves the problems of complex and low efficiency of resistivity calculation in the prior art, and achieves fast and accurate calculation of resistivity.

[0118] Each module in the resistivity detection device 100 can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0119] The present application also provides an electronic device, which may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 9As shown. The electronic device includes a processor, memory, a communication interface, a display, and an input device connected via a system bus. The processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a computer-readable storage medium and internal memory. The computer-readable storage medium stores an operating system and computer-executable instructions. The internal memory provides an environment for the operation of the operating system and computer-executable instructions in the computer-readable storage medium. The communication interface of the electronic device is used to communicate with an external terminal via wired or wireless communication. The wireless communication can be achieved via Wi-Fi, a mobile cellular network, NFC (near-field communication), or other technologies. When executed by the processor, the computer program implements any of the above-mentioned sample resistivity detection methods. The display of the electronic device can be a liquid crystal display or an electronic ink display. The input device of the electronic device can be a touch layer covering the display, a key, trackball, or touchpad provided on the electronic device housing, or an external keyboard, touchpad, or mouse.

[0120] It should be noted that the above-mentioned computer-readable storage medium implementation method and the above-mentioned method implementation method belong to the same concept. The specific implementation process is detailed in the method implementation method, and the technical features in the method implementation method are applicable in the device implementation method, which will not be repeated here.

[0121] The above is a detailed introduction to a method, device, electronic device and storage medium for detecting the resistivity of a wafer provided by the present invention. The various embodiments in this application specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device, electronic device and storage medium disclosed in the embodiments of the present application, since they correspond to the methods disclosed in the embodiments of the present application, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0122] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims appended to this application.

Claims

1. A method for detecting wafer resistivity, characterized in that: include: Fixing the sample to be tested on the detection platform (10) so that the sample to be tested can reciprocate along a preset direction under the drive of the detection platform (10); When the sample to be tested moves to below the sampling unit (30), the sample to be tested is controlled to move relative to the sampling unit (30) along a first preset direction, so that the sampling unit (30) samples a plurality of first sampling points on the sample to be tested at intervals to determine a detection voltage at each of the first sampling points; Controlling the sample to be tested to rotate around its axis by a set angle, controlling the sample to be tested to move relative to the sampling unit (30) along a second preset direction, so that the sampling unit (30) samples a plurality of second sampling points on the sample to be tested at intervals to determine a detection voltage at each second sampling point, wherein the second preset direction is opposite to the first preset direction; When determining the no-load voltage of the sampling unit (30), determining the reference voltage of each sampling point based on the difference between the detection voltage of each sampling point and the no-load voltage; Obtain two calibration samples with the highest resistivity and the lowest resistivity from the sample library; When the reference voltage, thickness, and resistivity of the two calibration samples are determined, a first fixed coefficient and a second fixed coefficient in the resistivity calculation formula are obtained, and the first fixed coefficient satisfies the following relationship: The second fixed coefficient satisfies the following relationship: ; Wherein, V1 is the reference voltage of calibration sample 1, V2 is the reference voltage of calibration sample 2, T1 is the thickness of calibration sample 1, T2 is the thickness of calibration sample 2, R1 is the resistivity of calibration sample 1, and R2 is the resistivity of calibration sample 2; Substitute the thickness of the sample to be tested and the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point. The resistivity calculation formula satisfies the following relationship: ; In the formula, R represents the resistivity, K represents the first fixed coefficient, T represents the thickness of the sample to be tested, V represents the reference voltage, and B represents the second fixed coefficient.

2. The method according to claim 1, characterized in that The method further comprises: The number of sampling points is increased or decreased by increasing or decreasing the number of rotations of the sample to be tested.

3. The method according to claim 1, characterized in that The process of determining the detection voltage of each of the first sampling points includes: Determining the position of a first sampling point so that the sampling unit (30) samples the first initial voltages on both sides of the first sampling point at intervals; determining an average value of a plurality of the first initial voltages as a detection voltage of the first sampling point; The process of determining the detection voltage of each second sampling point includes: Determining the position of a second sampling point so that the sampling unit (30) samples a second initial voltage on both sides of the second sampling point at intervals; An average value of a plurality of second initial voltages is determined as a detection voltage of a second sampling point.

4. The method according to claim 3, characterized in that The process of the sampling unit (30) sampling the first initial voltages at both sides of the first sampling point at intervals includes: When one of the first sampling points approaches the sampling unit (30) along the first preset direction, if the first sampling point reaches a first preset distance from the sampling unit (30), the sampling unit (30) starts to collect the first initial voltage at intervals; When one of the first sampling points is away from the sampling unit (30) along the first preset direction, if the first sampling point reaches a second preset distance from the sampling unit (30), the sampling unit (30) stops collecting the first initial voltage, and the first preset distance is equal to the second preset distance.

5. The method according to claim 1, wherein The method further comprises: determining a resistivity interval of the two calibration samples; When determining the resistivity of each sampling point, if the resistivity of the sampling point is outside the resistivity range, the calibration sample is replaced.

6. The method according to claim 1, characterized in that The process of controlling the sample to be tested to rotate around its axis at a set angle includes: The sample to be tested is lifted upward by an adjustment unit (20) provided below the testing platform (10), so that the sample to be tested leaves the testing platform (10); The adjustment unit (20) rotates around the axis of the sample to be tested to drive the sample to be tested to rotate the set angle; The sample to be tested is placed on the adjustment platform after being rotated to the set angle.

7. A wafer resistivity detection device, characterized in that: include: A testing platform (10) is used to carry a sample to be tested, so that the sample to be tested can reciprocate along a preset direction under the drive of the testing platform (10); An adjusting unit (20) is used to control the sample to be tested to rotate around its own axis to a set angle; The sampling unit (30) is used to sample a plurality of first sampling points on the sample to be tested at intervals. When the sample to be tested moves to the bottom of the sampling unit (30), the sample to be tested can move relative to the sampling unit (30) along a first preset direction to determine the detection voltage of each first sampling point. After the adjustment unit (20) controls the sample to be tested to rotate by the set angle, the sample to be tested can move relative to the sampling unit (30) along a second preset direction, so that the sampling unit (30) samples a plurality of second sampling points on the sample to be tested at intervals to determine the detection voltage of each second sampling point. The second preset direction is opposite to the first preset direction. A control module, configured to determine a reference voltage at each sampling point based on a difference between a detection voltage at each sampling point and the no-load voltage when the no-load voltage of the sampling unit (30) is determined; The first fixed coefficient and the second fixed coefficient in the resistivity calculation formula are obtained based on the reference voltage, thickness, and resistivity of the two calibration samples with the largest resistivity and the smallest resistivity in the sample library. The first fixed coefficient satisfies the following relationship: The second fixed coefficient satisfies the following relationship: Wherein, V1 is the reference voltage of calibration sample 1, V2 is the reference voltage of calibration sample 2, T1 is the thickness of calibration sample 1, T2 is the thickness of calibration sample 2, R1 is the resistivity of calibration sample 1, and R2 is the resistivity of calibration sample 2; The control module is further configured to substitute the thickness of the sample to be tested and the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point. The resistivity calculation formula satisfies the following relationship: ; Wherein, R represents the resistivity, K represents the first fixed coefficient, T represents the thickness of the sample to be tested, V represents the reference voltage, and B represents the second fixed coefficient; Based on a pre-established resistivity calculation formula, the reference voltage of each sampling point is substituted into the resistivity calculation formula to obtain the resistivity of each sampling point.

8. An electronic device, characterized in that: include: A memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the method according to any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium storing computer-executable instructions, wherein: The computer-executable instructions are used to enable a computer to execute the method according to any one of claims 1 to 6.

Images