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

Abstract

The invention discloses a wafer resistivity detection method and device, electronic equipment and a storage medium, and the detection method comprises the steps: enabling a to-be-detected sample to be fixed on a detection platform, and enabling the to-be-detected sample to be driven by the detection platform to move in a reciprocating manner in a preset direction; when the to-be-tested sample sheet moves to the position below the sampling unit, the to-be-tested sample sheet is controlled to move in the first preset direction, so that the sampling unit samples sampling points on the to-be-tested sample sheet at intervals; the to-be-detected sample is controlled to rotate around the axis of the to-be-detected sample by a set angle, the to-be-detected sample is controlled to move relative to the sampling unit in the second preset direction, the sampling unit samples the sampling points on the to-be-detected sample at intervals, and the second preset direction is opposite to the first preset direction; determining a reference voltage of the sampling point based on a difference value between the detection voltage of the sampling point and the no-load voltage; and substituting the reference voltage into a pre-established resistivity calculation formula to obtain the resistivity. According to the detection method, the detection efficiency of the wafer resistivity is higher, and the detection method has higher precision.

Description

Technical Field

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

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

[0003] However, the existing methods for detecting the resistivity of silicon carbide wafers have certain limitations. The existing resistivity detection devices generally have problems such as low detection efficiency and few sampling points. Usually, they can only perform single-direction and single-time detection on the sample to be measured, resulting in poor representativeness of the detection results and inability to comprehensively reflect the electrical performance of silicon carbide wafers. In addition, when the existing equipment performs resistivity detection, the substrate conveying time of the equipment is relatively long, and each process of placing and adjusting the sample to be measured requires additional time, which is not continuous and efficient enough, and the overall detection rhythm is slow, thus affecting the efficiency of the production line and unable to meet the requirements of high-speed production and large-scale detection. Summary of the Invention

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

[0005] To achieve the above purpose, this application adopts the following technical solutions: In the first aspect, this application provides a method for detecting the resistivity of a wafer, the method comprising: Fix the sample to be measured on the detection platform so that the sample to be measured can reciprocate along a preset direction under the drive of the detection platform; When the sample to be measured moves below the sampling unit, control the sample to be measured 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 measured at intervals to determine the detection voltage of each first sampling point; Control the sample under test to rotate by a set angle around its axis, and control the sample under test to move relative to the sampling unit in a second preset direction, so that the sampling unit samples several second sampling points on the sample under test at intervals to determine the detection voltage of each second sampling point. The second preset direction is opposite to the first preset direction; Under the condition of determining the no-load voltage of the sampling unit, determine the reference voltage of each sampling point based on the difference between the detection voltage and the no-load voltage of each sampling point; Based on the pre-established resistivity calculation formula, substitute the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point.

[0006] Further, the method further includes: By increasing or decreasing the number of rotations of the sample under test, increase or decrease the number of sampling points.

[0007] Further, in the process of determining the detection voltage of each first sampling point, it includes: determining the position of a first sampling point, and making the sampling unit sample the first initial voltages on both sides of a first sampling point at intervals; determining the average value of several first initial voltages as the detection voltage of a first sampling point; In the process of determining the detection voltage of each second sampling point, it includes: determining the position of a second sampling point, and making the sampling unit sample the second initial voltages on both sides of a second sampling point at intervals; determining the average value of several second initial voltages as the detection voltage of a second sampling point.

[0008] Further, in the process of the sampling unit sampling the first initial voltages on both sides of a first sampling point at intervals, it includes: when a first sampling point approaches the sampling unit in the first preset direction, if the distance between the first sampling point and the sampling unit reaches the first preset distance, the sampling unit starts to sample the first initial voltages at intervals; when a first sampling point moves away from the sampling unit in the first preset direction, if the distance between the first sampling point and the sampling unit reaches the second preset distance, the sampling unit stops sampling the first initial voltages. The first preset distance is equal to the second preset distance.

[0009] Further, in the process of determining the pre-established resistivity calculation formula, it includes: obtaining two calibration samples with the maximum and minimum resistivity from the sample library; under the condition of determining the reference voltage, thickness and resistivity of the two calibration samples respectively, obtaining the first fixed coefficient and the second fixed coefficient in the resistivity calculation formula. The resistivity calculation formula satisfies the following relationship: ; where, R represents resistivity, K represents the first fixed coefficient, T represents thickness, V represents reference voltage, and B represents the second fixed coefficient.

[0010] Further, the method further includes: determining the resistivity ranges of two calibration samples; when determining the resistivity of each sampling point, if the resistivity of the sampling point is outside the resistivity range, replacing the calibration sample.

[0011] Further, during the process of controlling the sample to be measured to rotate by a set angle around its axis, it includes: jacking up the sample to be measured upward by an adjustment unit arranged under the detection platform, so that the sample to be measured leaves the detection platform; the adjustment unit rotates around the axis of the sample to be measured to drive the sample to be measured to rotate by the set angle; placing the sample to be measured after rotating the set angle on the adjustment platform.

[0012] In a second aspect, the present application further provides a device for detecting the resistivity of a wafer, and the device includes: A detection platform for carrying the sample to be measured, so that the sample to be measured can reciprocate along a preset direction under the drive of the detection platform; An adjustment unit for controlling the sample to be measured to rotate by a set angle around its own axis; A sampling unit for sampling several first sampling points on the sample to be measured at intervals. When the sample to be measured moves below the sampling unit, the sample to be measured can move relative to the sampling unit along a first preset direction to determine the detection voltage of each first sampling point; after controlling the sample to be measured to rotate by the set angle through an adjustment device, the sample to be measured can move relative to the sampling unit along a second preset direction, so that the sampling unit samples several second sampling points on the sample to be measured at intervals to determine the detection voltage of each second sampling point, and the second preset direction is opposite to the first preset direction; A control module for, when 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 of each sampling point and the no-load voltage; substituting the reference voltage of each sampling point into a resistivity calculation formula based on a pre-established resistivity calculation formula to obtain the resistivity of each sampling point.

[0013] In a third aspect, the present application further provides an electronic device, and the device includes: A memory and a processor, the memory stores a computer program, and it is characterized in that when the processor executes the computer program, the steps of the method in any one of the methods for detecting the resistivity of a sample in the first aspect are implemented.

[0014] In a fourth aspect, the present application further provides a computer-readable storage medium, and the computer-readable storage medium stores computer-executable instructions for causing a computer to execute the method in any one of the methods for detecting the resistivity of a sample in the first aspect.

[0015] The method for detecting the resistivity of a wafer provided by this application drives the sample to be measured to reciprocate relative to the sampling unit, and controls the sample to be measured to rotate after each lateral movement in one direction of the sample to be measured, so as to adjust the angle of the sample to be measured, optimize the detection path, improve the detection efficiency, and effectively reduce the deviation of one-way sampling. Based on this detection method, a larger number of sampling points can be obtained in a complete sampling working hour, improving the accuracy and reliability of the measurement results. Description of the Drawings

[0016] Figure 1 It is a flowchart of the resistivity detection method in the embodiment of this application; Figure 2 It is a schematic structural diagram of the resistivity detection device in the embodiment of this application; Figure 3 It is a schematic diagram of several sampling points in the embodiment of this application; Figure 4 It is a flowchart of the acquisition unit acquiring the initial voltages on both sides of the first sampling point in the embodiment of this application; Figure 5 It is a flowchart for determining the pre-established resistivity calculation formula; Figure 6 It is a flowchart for determining the resistivity range in the resistivity detection method in the embodiment of this application; Figure 7 It is a flowchart for controlling the sample to be measured to rotate a set angle around its axis in the embodiment of this application; Figure 8 It is a schematic structural diagram of the resistivity detection device at another angle in the embodiment of this application; Figure 9 It is the internal structure diagram of the electronic device in the embodiment of this application.

[0017] Reference Numerals: 100, resistivity detection device; 10, detection platform; 11, silicon carbide base plate; 12, lead 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 Embodiments

[0018] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the specific embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0019] It should be noted that the orientation nouns such as up, down, left, right, front, and back, or ordinal numbers such as "first, second, third, fourth", etc., mentioned in this article are all based on the accompanying drawings of the specification as a reference and are introduced for the convenience of description, and do not mean any limitation on the order of components. In addition, since the functions of some parts between the components provided in the above embodiments are the same, the present specification uses a unified naming method for these parts. The above has introduced in detail the pipeline connection device provided by the related technical solution. Specific embodiments are used in this article for elaboration. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, and does not impose any formal limitation on the present invention.

[0020] As Figure 2 shown, the present application provides a resistivity detection device 100. In order to clearly illustrate the technical solution of the present invention, the up and down, left and right, front and back directions as shown in Figure 2 are also defined as the up and down, left and right, front and back directions of the resistivity detection device 100. In the description of the present application, the width direction of the resistivity detection device 100 is the Figure 2 front and back direction as shown, the height direction of the resistivity detection device 100 is the Figure 1 up and down direction as shown, and the length direction of the resistivity detection device 100 is the Figure 1 left and right direction as shown.

[0021] As Figure 1 shown, the present application provides a method for detecting the resistivity of a wafer, including the following steps: Step S101: Fix the sample to be measured on the detection platform 10 so that the sample to be measured can reciprocate along a preset direction under the drive of the detection platform 10.

[0022] As Figure 2 shown, exemplarily, the sample to be measured is set as at least one of 6-inch / 8-inch silicon carbide wafers. The detection platform 10 includes a silicon carbide bottom plate 11, a lead screw module 12, and a connecting plate 13. The sample to be measured is placed on the silicon carbide bottom plate 11. The lead screw module 12 is connected to the connecting plate 13. The lead screw module 12 is used to drive the detection platform 10 to reciprocate along a preset direction. The connecting plate 13 fixes the lead screw module 12 and the silicon carbide bottom plate 11 to ensure the stability of the reciprocating motion of the lead screw module 12. The detection platform 10 drives the sample to be measured to reciprocate through the reciprocating motion of the lead screw module 12, so that the sample to be measured can reciprocate along a preset direction.

[0023] Step S102: When the sample to be measured moves below the sampling unit 30, control the sample to be measured to move relative to the sampling unit 30 along a first preset direction, so that the sampling unit 30 samples a number of first sampling points on the sample to be measured at intervals, to determine the detection voltage of each first sampling point.

[0024] As Figure 2 shown, exemplarily, the sampling unit 30 is used to sample the detection voltage of the sample to be measured. The sampling unit 30 includes a resistivity probe 31 and a positioning sensor (not shown in the figure). At least part 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 between the sampling unit 30 and a number of first sampling points on the sample to be measured in the first preset direction. This displacement distance is used to determine when the sampling unit 30 starts / stops detecting, so as to accurately position the spacing between a number of first sampling points by the resistivity probe 31. It should be noted that the first preset direction refers to the movement direction of the sample to be measured on the detection platform 10. By controlling the detection platform 10 to move along the first preset direction, the sample to be measured moves in the first preset direction. The sampling of the sampling unit 30 is carried out at intervals, and the interval is preset by software.

[0025] Exemplarily, when sampling one of the first sampling points, when the sample to be measured moves to a position 1 mm close to the first sampling point of the sampling unit 30, the sampling unit 30 starts to detect. When the sample to be measured moves to a position 1 mm away from the first sampling point of the sampling unit 30, the sampling unit 30 stops detecting. The sampling density of the sampling points will follow the principle of uniform distribution. For example, 20 sampling points are formed between the position 1 mm close to the first sampling point and the position 1 mm away from the first sampling point. After the sampling unit 30 detects 20 voltage data, the average value is obtained, and this average value is used as the detection voltage of the first sampling point.

[0026] Step S103: Control the sample to be measured to rotate a set angle around its axis, control the sample to be measured to move relative to the sampling unit 30 along a second preset direction, so that the sampling unit 30 samples a number of second sampling points on the sample to be measured at intervals, to determine the detection voltage of each second sampling point. The second preset direction is opposite to the first preset direction.

[0027] As Figure 2As shown, exemplarily, the adjustment unit 20 is used to control the sample to be measured to rotate a set angle around its axis. 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. A receiving space 111 for the vertical passage of the ceramic suction cup 22 is provided in the silicon carbide bottom plate 11. 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 measured from the silicon carbide bottom plate 11. A plurality of vacuum chambers 221 are provided in the ceramic suction cup 22. By pumping out the air in the vacuum chamber 111, a negative pressure is formed in the vacuum chamber 221. Under the action of the atmospheric pressure, the sample to be measured is adsorbed on the ceramic suction cup 22 by vacuum adsorption, thereby fixing the sample to be measured. The ceramic suction cup 22 is driven by the rotation drive assembly 23 to rotate a set angle around its own axis. An encoder is provided in the rotation drive assembly 23. The encoder is used to feedback the preset rotation angle, so as to accurately control the angle of each rotation.

[0028] As Figure 3 shown, after the sampling unit 30 completes the sampling of the sample to be measured along the first preset direction, when the rotation drive assembly 23 drives the sample to be measured to rotate a set angle (such as 15°), the next round of voltage sampling is prepared. When the sample to be measured completes the rotation, the detection platform 10 will control the sample to move smoothly along the second preset direction (the second preset direction is opposite to the first preset direction). Among them, Figure 3 the numbers in represent the sampling path. The sample to be measured is detected by moving in a single direction reciprocally and adjusting the detection path by rotation. This method can ensure that after each rotation, the sampling unit 30 can measure the voltage of the sampling point at the new position in the shortest time. Through this setting, the sampling unit 30 can achieve higher sampling efficiency within the unit sampling time.

[0029] Step S104: Based on the difference between the detection voltage of each sampling point and the no-load voltage, determine the reference voltage of each sampling point when the no-load voltage of the sampling unit 30 is determined.

[0030] Specifically, the no-load voltage refers to the voltage value obtained by the sampling unit 30 when measuring the air without sampling the sample to be measured. The no-load voltage needs to be calibrated before each detection, and the ambient temperature is controlled at 25°C ± 1°C and the humidity ≤ 50% to exclude environmental interference. The measurement of the no-load voltage is to ensure the basic voltage state of the sampling unit 30 without external influence. During this process, the no-load voltage is directly read by the resistivity probe without contacting the sample to be measured. The calculation formula of the reference voltage is ; where is the reference voltage of the sampling point, is the detection voltage of the sampling point, is the no-load voltage of the sampling point.

[0031] Step S105: Based on the pre-established resistivity calculation formula, substitute the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point.

[0032] Specifically, before actual detection, measure the respective resistivities and thicknesses of the two silicon wafers with the maximum and minimum resistivities in the sample library as known conditions. Take these two silicon wafers as calibration samples. The calibration method is to move the center position of the calibration sample under the sampling unit 30 and start collecting voltage. , subtract the no-load voltage from the detected voltage of the calibration sample to obtain the required reference voltage. It should be noted that the no-load voltage is the output voltage when the sampling unit 30 does not contact the sample to be measured, and the detected voltage is the output voltage when the sampling unit 30 samples the sample to be measured. After calibrating the two calibration samples, obtain the value of the first fixed coefficient K, and then use the obtained value of the first fixed coefficient K to calculate the value of the second fixed coefficient B, and further obtain the values of the first fixed coefficient K and the second fixed coefficient B. The resistivity calculation formula involves the thickness of the sample to be measured, the voltage difference, and the resistivity coefficient of the material. Substitute the reference voltage of the sampling point of the sample to be measured into the resistivity calculation formula. ; where R represents the resistivity to be obtained, K represents the first fixed coefficient, calculated based on the data of the calibration sample, T represents the thickness of the sample to be measured, V represents the reference voltage, calculated by the voltage difference and the no-load voltage of each sampling point, and B represents the second fixed coefficient, calculated based on the data of the calibration sample. Under the condition of determining the first fixed coefficient K, the second fixed coefficient B, and the thickness T of the sample to be measured, substitute the reference voltage V of the sample to be measured to obtain the resistivity of each sampling point.

[0033] In the embodiment of the present application, the detection method drives the sample to be measured to reciprocate relative to the sampling unit 30, and controls the sample to be measured to rotate after each lateral movement in one direction of the sample to be measured to adjust the angle of the sample to be measured, optimizes the detection path, improves the detection efficiency, and effectively reduces the deviation of single-direction sampling. The combination of rotation and movement effectively increases the coverage range of the detection path, ensuring that the resistivities of all regions of the sample to be measured can be comprehensively detected. Based on this detection method, more sampling points can be obtained in a complete sampling working hour, improving the accuracy and reliability of the measurement results.

[0034] As an implementation, by increasing or decreasing the number of rotations of the sample to be measured, the number of sampling points can be increased or decreased.

[0035] Specifically, by changing the number of rotations of the sample to be measured, when the sample to be measured rotates, the sampling unit 30 will perform voltage sampling at certain intervals on the surface of the sample. Each change in the rotation angle will result in a change in the distribution of sampling points. By adjusting the rotation angle, the number of sampling points can be increased or decreased. For example, if it rotates 15° each time, then after each rotation, the sampling unit 30 will collect new sampling points on the sample. If the rotation angle is reduced to 10°, the number of samplings per time increases because more sampling points can be captured within the same rotation range. On the contrary, if the rotation angle is increased to 30°, the number of samplings per time decreases, saving the 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.

[0036] In the embodiment of the present application, by increasing or decreasing the number of rotations of the sample to be measured, the number of sampling points is flexibly controlled, realizing the adaptability and adjustability of the detection method. Through the above settings, the flexibility of the resistivity detection method is enhanced, and the number of sampling points can be adjusted according to different detection requirements, thereby optimizing the balance between detection accuracy and detection efficiency in the resistivity detection process.

[0037] As an implementation method, in the process of determining the detection voltage of each first sampling point, it includes: determining the position of a first sampling point, so that the sampling unit 30 samples the first initial voltages on both sides of a first sampling point at intervals; determining the average value of several first initial voltages as the detection voltage of a first sampling point; In the process of determining the detection voltage of each second sampling point, it includes: determining the position of a second sampling point, so that the sampling unit 30 samples the second initial voltages on both sides of a second sampling point at intervals; determining the average value of several second initial voltages as the detection voltage of a second sampling point.

[0038] Specifically, in the process of determining the detection voltage of each sampling point, the sampling unit 30 will sample the voltages on both sides of each sampling point and take their 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 small deviations of the equipment and unevenness of the surface of the sample to be measured may cause the measured value of a single sampling point to be too high or too low. By collecting data at multiple positions on both sides of the sampling point at intervals and calculating the average value, local non-uniformities and errors will be smoothed, making the finally measured voltage value more accurate and real. At the same time, this method can obtain data in a wider area, making the detection voltage of each sampling point not only reflect the situation of a certain local area, but also reflect the overall electrical performance 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.

[0039] In an embodiment of the present application, a method for accurately sampling the voltage of a sampling point of a sample to be measured is provided. This method samples the voltages on both sides of each sampling point and takes their average value as the final detected voltage. Averaging multiple voltage values measured on both sides of the sampling point can reduce the influence caused by single measurement errors or local non-uniformities, thereby improving the accuracy of the detected voltage measurement, reducing local errors, enhancing the representativeness and reliability of the sampling point, and ensuring the accuracy of the detected voltage measurement.

[0040] As Figure 4 shown, as an implementation manner, during the process of the sampling unit 30 intermittently sampling the first initial voltages on both sides of a first sampling point, the following steps are included: Step S301: When a first sampling point approaches the sampling unit 30 along a first preset direction, if the first sampling point is at a first preset distance from the sampling unit 30, the sampling unit 30 starts to intermittently collect the first initial voltages.

[0041] Specifically, the first preset distance refers to the specific distance between the point where the sampling of the sample to be measured starts and the sampling unit 30 when the sample to be measured approaches the sampling unit 30 along the first preset direction. When the sample to be measured approaches, the sampling unit 30 starts sampling when the distance between the sampling point of the sample to be measured and the sampling unit 30 reaches the first preset distance. For example, the PLC control system monitors the actual position of the moving mechanism. When the sampling point of the sample to be measured moves to a position 1 mm away from the sampling unit 30, sampling starts.

[0042] Step S302: When a first sampling point moves away from the sampling unit 30 along the first preset direction, if the first sampling point is at a second preset distance from the sampling unit 30, the sampling unit 30 stops collecting the first initial voltages, and the first preset distance is equal to the second preset distance.

[0043] Specifically, the second preset distance refers to the specific distance between the point where the sampling of the sample to be measured starts and the sampling unit 30 when the sample to be measured moves away from the sampling unit 30 along the first preset direction. When the sample to be measured moves away from the sampling unit 30, the sampling unit 30 stops sampling when the distance between the sampling point of the sample to be measured and the sampling point reaches the second preset distance. For example, the PLC control system monitors the actual position of the moving mechanism. When the sampling point of the sample to be measured moves to a position 1 mm away from the sampling unit 30, sampling ends. The equality of the first preset distance and the second preset distance means that the sampling start and stop distance ranges of the sampling unit 30 are the same.

[0044] In the embodiment of the present application, by controlling the distance between the sample to be measured and the sampling unit 30, the start and end timing of sampling are accurately controlled, redundant sampling of irrelevant areas is avoided, sampling waste is reduced, and the accuracy of sampling data is improved. The first preset distance is equal to the second preset distance, so that during the sampling process of the sampling unit 30, the sampling ranges on both sides of the sampling unit 30 are kept consistent, thereby reducing the measurement error of the voltage data of each sampling point, providing more accurate sampling data, and further improving the reliability of the resistivity measurement result.

[0045] As Figure 5 shown, as an implementation manner, in the process of determining the pre-established resistivity calculation formula, the following steps are included: Step S401: Obtain two calibration samples with the maximum and minimum resistivity from the sample library; Specifically, the sample library is a collection of calibration samples with known resistivity, thickness, and voltage characteristics. Each calibration sample has been tested in detail, and the electrical properties and physical characteristics (such as resistivity, thickness, reference voltage) of each calibration sample have been measured and recorded. The calibration samples are used to calibrate the resistivity measurement method and equipment. The sample library provides a standardized benchmark to ensure the accuracy of the resistivity measurement method. By selecting the calibration sample with the maximum resistivity as calibration sample one and the calibration sample with the minimum resistivity as calibration sample two, for the sample to be measured, the detection results of all resistivity ranges can be covered.

[0046] Step S402: When the reference voltage, thickness, and resistivity of the two calibration samples are determined, obtain the first fixed coefficient and the second fixed coefficient in the resistivity calculation formula; Specifically, the resistivity calculation formula satisfies the following relationship: , through the known data of the calibration sample, the first fixed coefficient K and the second fixed coefficient B can be deduced inversely through 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 the 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. When the reference voltage, thickness, and resistivity of the two calibration samples are known, substitute them into the basic calculation formula:

[0047]

[0048] Among them, V1 is the reference voltage of calibration sample 1; V2 is the reference voltage of calibration sample 2; the reference voltage is the difference between the detected voltage and the no-load voltage; T1 is the thickness of calibration sample 1; T2 is the thickness of calibration sample 2; R1 is the resistivity of calibration sample 1; R2 is the resistivity of calibration sample 2; the first fixed coefficient K and the second fixed coefficient B are values to be determined.

[0049] Calculation of the first fixed coefficient K:

[0050] Calculation of the second fixed coefficient B:

[0051] Based on the known voltage, thickness, and resistivity data of the calibration samples, the specific values of the first fixed coefficient and the second fixed coefficient can be calculated. For example, the thickness T1 of calibration sample 1 = 336.5 μm, the resistivity R1 of calibration sample 1 = 0.3238 Ω·cm, the reference voltage V1 of calibration sample 1 = 8.712 V, the thickness T2 of calibration sample 2 = 300.6 μm, the resistivity R2 of calibration sample 2 = 1.1960 Ω·cm, and the reference voltage V2 of calibration sample 2 = 2.039 V. The first fixed coefficient K = (8.712 - 2.039) / (336.5 / 0.3238 - 300.6 / 1.1960) = 0.00846952; The second fixed coefficient B = 8.712 - 0.00846952 * 336.5 / 0.3238 = 0.08971082; Step S403: The resistivity calculation formula satisfies the following relationship: ; In the formula, R represents resistivity, K represents the first fixed coefficient, T represents thickness, V represents the reference voltage, and B represents the second fixed coefficient.

[0052] Specifically, the resistivity calculation formula satisfies the following relationship: ; Among them, the values of the first fixed coefficient K and the second fixed coefficient B can be obtained through the above step S402, which will not be elaborated here. T is the thickness of the sample to be measured, V represents the reference voltage of the sample to be measured. The thickness T of the sample to be measured is directly measured by a mechanical measuring instrument for the sample to be measured. For example, a micrometer or a caliper is used for direct measurement. This method determines the thickness by directly contacting the upper and lower surfaces of the sample to be measured and is applicable to most samples to be measured with standard thicknesses. V is the reference voltage of the sample to be measured, and the detection is performed by referring to the methods provided in other embodiments of this application, which will not be elaborated here. Through the resistivity calculation formula, by substituting the values of the first fixed coefficient K, the second fixed coefficient B, the thickness T of the sample to be measured, and the reference voltage V, the resistivity R of the sample to be measured can be obtained.

[0053] For example, the thickness T of the sample to be measured is 298.9 μm, and the measured reference voltage V is 3.927 V. Calculate the resistivity R.

[0054] The resistivity R = K * T / (V - B) = 0.00846952 * 298.9 / (3.927 - 0.08971082) = 0.6597 Ω·cm.

[0055] In the embodiment of the present application, by using the calibration samples with the maximum and minimum resistivities to calculate the first fixed coefficient K and the second fixed coefficient B in the resistivity calculation formula, it is ensured that the resistivity calculation formula can adapt to the samples to be measured with different thicknesses and resistivity ranges, which can reduce the errors caused by equipment differences, environmental changes or calibration sample differences, and then obtain reliable measurement results in different resistivity ranges, improve the measurement accuracy, and improve the accuracy of the resistivity R of the sample to be measured.

[0056] Such as Figure 6 shown, as an implementation manner, the resistivity detection method of the sample to be measured further includes the following steps: Step S501: Determine the resistivity intervals of two calibration samples; Specifically, by selecting the calibration samples with the minimum and maximum resistivities, an interval covering the resistivity range of the sample to be measured 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 measured within the resistivity interval, the resistivity value calculated by the resistivity calculation formula will be reasonable and accurate. By setting the resistivity interval, it can be avoided that the resistivity calculation formula gives inaccurate measurements on the samples to be measured with resistivities outside the limit values. The setting of the resistivity interval enables the resistivity calculation formula to adapt to the common range of resistivities and not deviate from the actual material properties. Exemplarily, through actual tests, the reference voltages of calibration sample 1 and calibration sample 2 are detected, and their respective resistivities are determined by the method in the above embodiment to determine the resistivity intervals of the two calibration samples.

[0057] Step S502: When the resistivity of each sampling point is determined, if the resistivity of the sampling point is outside the resistivity interval, replace the calibration sample.

[0058] Specifically, if the resistivity of the sample to be measured exceeds the resistivity interval, the sample to be measured is replaced with a new calibration sample. For example, when the resistivity of the sample to be measured is higher than the resistivity of the calibration sample with the maximum resistivity, it is selected as the new calibration sample and added to the sample library. The resistivity of the new calibration sample can cover the new measurement range, thereby ensuring the accuracy and consistency of the measurement.

[0059] In the implementation mode of the present application, by introducing the resistivity interval and the mechanism of replacing the calibration sample, it can be ensured that the resistivity calculation formula can always maintain high accuracy within different resistivity ranges, thereby improving the accuracy of resistivity detection.

[0060] like Figure 7 As shown, as an implementation method, in the process of controlling the sample to be tested to rotate around its axis to a set angle, the following steps are included: Step S601: lift the sample to be tested upward by the adjustment unit 20 disposed under the detection platform 10, so that the sample to be tested leaves the detection platform 10; Specifically, the 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 started, and the piston rod lifts the ceramic suction cup and the sample to be tested upward to separate them from the detection platform 10, so as to eliminate 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.

[0061] 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; Specifically, the rotation drive assembly of the adjustment unit 20 also includes a first motor and a rotation bearing, and the first motor is connected to the ceramic suction cup. When the sample is lifted, the first motor drives the ceramic suction cup 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 the encoder, and the accuracy is controlled within ±0.1°. During the rotation process, the vacuum adsorption of the ceramic suction cup remains in the open state to prevent the sample to be tested from shifting.

[0062] Step S603: placing the sample to be tested after being rotated by a set angle on the adjustment platform.

[0063] Specifically, after the rotation is completed, the cylinder piston rod slowly descends, and the ceramic suction cup and the sample to be tested are placed back on the silicon carbide bottom plate. The ceramic suction cup releases vacuum adsorption, and the sample to be tested is slightly fixed by the elastic deformation of the silicon carbide bottom plate. Then the screw module is started, driving the sample to be tested to move along the second preset direction.

[0064] 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.

[0065] Based on the same inventive concept, an embodiment of the present application also provides a wafer resistivity detection device for implementing the above-mentioned wafer resistivity detection method. The solution provided by the resistivity detection device 100 for solving the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the wafer resistivity detection device provided below can refer to the limitations on the wafer resistivity detection method in the above text, and will not be elaborated here.

[0066] As Figure 8 shown, as an implementation manner, 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, where: The detection platform 10 is used to carry the sample to be measured, so that the sample to be measured can reciprocate along a preset direction under the drive of the detection platform 10; The adjustment unit 20 is used to control the sample to be measured to rotate a set angle around its own axis; The sampling unit 30 is used to sample several first sampling points on the sample to be measured at intervals. When the sample to be measured moves below the sampling unit 30, the sample to be measured can move relative to the sampling unit 30 along a first preset direction to determine the detection voltage of each first sampling point; after controlling the sample to be measured to rotate a set angle through the adjustment device, the sample to be measured can move relative to the sampling unit 30 along a second preset direction, so that the sampling unit 30 samples several second sampling points on the sample to be measured at intervals to determine the detection voltage of each second sampling point, and the second preset direction is opposite to the first preset direction; The control module is used to, when determining the no-load voltage of the sampling unit 30, determine the reference voltage of each sampling point based on the difference between the detection voltage of each sampling point and the no-load voltage; based on the pre-established resistivity calculation formula, substitute the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point.

[0067] As Figure 8 shown, as an implementation manner, the detection platform 10 is used to carry the sample to be measured and ensure that the sample can reciprocate along a preset direction during the detection process.

[0068] During the detection process, the detection platform 10 drives through the lead screw module 12 to move the sample to be measured along the first preset direction below the sampling unit 30. At this time, the sampling unit 30 collects the voltage of the first sampling point. After the collection is completed, the adjustment unit 20 is started to lift and rotate the sample to be measured by a set angle (such as 15°), and then it is placed back on the detection platform 10. At this time, the detection platform 10 moves along the second preset direction, and the sampling unit 30 collects the voltage of the second sampling point.

[0069] 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.

[0070] Furthermore, the adjustment unit 20 is used to control the sample to be tested to rotate around its axis to a set angle. During the operation of the adjustment unit 20, the cylinder 21 first lifts the ceramic suction cup 22 and the sample to be tested to separate them from the detection platform 10. Subsequently, the first motor drives the ceramic suction cup 22 and the sample to be tested to rotate around the central axis to a set angle. After the rotation is completed, the cylinder 21 descends and the sample to be tested is placed back on the silicon carbide base plate 11. At this time, the detection platform 10 moves along the second preset direction, and the sampling unit 30 collects voltage at the second sampling point.

[0071] In the embodiment of the present application, the 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.

[0072] Furthermore, the sampling unit 30 is used to sample a plurality of first sampling points and a second sampling point on the test sample at intervals. During the sampling process, when the detection platform 10 drives the test sample to move to the bottom of the resistivity probe 31, the control module controls the sampling unit to start voltage collection at a distance of 1 mm from the sampling point, and stops collecting after moving more than 1 mm. 20 sets of voltage data are collected at each sampling point, and the average value is calculated as the detection voltage by the control module, and the no-load voltage (the output voltage when the resistivity probe is suspended) is deducted in real time.

[0073] In the implementation mode of the present application, bidirectional sampling of the sample to be tested is realized through precise control of the control module. In the implementation mode, the voltage sampling improves the measurement accuracy through the average value method, solves the problem of small number of sampling points and low detection efficiency in the prior art, and realizes multi-point sampling and high-precision detection.

[0074] 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 calibration samples to ensure the detection accuracy.

[0075] In the embodiment of the present application, through the automated calculation function of the control module, the problems of complex resistivity calculation and low efficiency in the prior art are solved, and rapid and accurate calculation of resistivity is achieved.

[0076] Each module in the above resistivity detection device 100 can be implemented in whole or in part by software, hardware, and their combination. Each of the above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0077] The present application also provides an electronic device. The electronic device can be a terminal, and its internal structure diagram can be as Figure 9 shown. The electronic device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, 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 an 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 in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it realizes any one of the above sample resistivity detection methods. The display screen of the electronic device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic device can be a touch layer covering the display screen, or can be a button, a trackball, or a touchpad provided on the housing of the electronic device, or can also be an external keyboard, a touchpad, or a mouse, etc.

[0078] It should be noted that the above computer-readable storage medium embodiment and the above method embodiment belong to the same concept. For the specific implementation process, please refer to the method embodiment, and the technical features in the method embodiment are correspondingly applicable to the device embodiment, and will not be elaborated here.

[0079] The above has introduced in detail a method, device, electronic device and storage medium for detecting the resistivity of a wafer. The various embodiments in the specification of this application are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other. For the device, electronic device and storage medium disclosed in the embodiments of this application, since they correspond to the method disclosed in the embodiments of this application, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0080] It should be understood that for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of this application.

Claims

1. A method for detecting the resistivity of a wafer, characterized in that, Including: Fix the sample to be measured on the detection platform (10) so that the sample to be measured can reciprocate along a preset direction driven by the detection platform (10); When the sample to be measured moves below the sampling unit (30), control the sample to be measured to move relative to the sampling unit (30) along a first preset direction, so that the sampling unit (30) samples a number of first sampling points on the sample to be measured at intervals to determine the detection voltage of each first sampling point; Control the sample to be measured to rotate a set angle around its axis, control the sample to be measured to move relative to the sampling unit (30) along a second preset direction, so that the sampling unit (30) samples a number of second sampling points on the sample to be measured at intervals to determine the detection voltage of each second sampling point, and the second preset direction is opposite to the first preset direction; In the case of determining the no-load voltage of the sampling unit (30), determine the reference voltage of each sampling point based on the difference between the detection voltage of each sampling point and the no-load voltage; Based on the pre-established resistivity calculation formula, substitute the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point.

2. The method according to claim 1, wherein: The method further includes: By increasing or decreasing the number of rotations of the sample to be measured, the number of sampling points is increased or decreased.

3. The method according to claim 1, wherein: In the process of determining the detection voltage of each first sampling point, it includes: Determine the position of a first sampling point, so that the sampling unit (30) samples the first initial voltages on both sides of a first sampling point at intervals; Determine the average value of a number of the first initial voltages as the detection voltage of a first sampling point; In the process of determining the detection voltage of each second sampling point, it includes: Determine the position of a second sampling point, so that the sampling unit (30) samples the second initial voltages on both sides of a second sampling point at intervals; Determine the average value of a number of the second initial voltages as the detection voltage of a second sampling point.

4. The method according to claim 3, wherein: In the process of the sampling unit (30) sampling the first initial voltages on both sides of a first sampling point at intervals, it includes: When a first sampling point approaches the sampling unit (30) along the first preset direction, if the first sampling point is at a first preset distance from the sampling unit (30), the sampling unit (30) starts to sample the first initial voltages at intervals; When a first sampling point moves away from the sampling unit (30) along the first preset direction, if the first sampling point is at a second preset distance from the sampling unit (30), the sampling unit (30) stops sampling the first initial voltages, and the first preset distance is equal to the second preset distance.

5. The method according to claim 1, wherein: In the process of determining the pre-established resistivity calculation formula, it includes: Obtaining two calibration specimens with the maximum and minimum resistivity from the specimen library; When determining the reference voltage, thickness, and resistivity of each of the two calibration specimens, obtaining the first fixed coefficient and the second fixed coefficient in the resistivity calculation formula, and 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, V represents the reference voltage, and B represents the second fixed coefficient.

6. The method according to claim 5, wherein: The method further includes: Determining the resistivity range of the two calibration specimens; When determining the resistivity of each sampling point, if the resistivity of the sampling point is outside the resistivity range, replacing the calibration specimen.

7. The method according to claim 1, wherein: In the process of controlling the specimen to be measured to rotate a set angle around its axis, it includes: Lifting the specimen to be measured upward by an adjusting unit (20) arranged below the detection platform (10) so that the specimen to be measured leaves the detection platform (10); The adjusting unit (20) rotates around the axis of the specimen to be measured to drive the specimen to be measured to rotate the set angle; Placing the specimen to be measured after rotating the set angle on the adjusting platform.

8. A detecting device for the resistivity of a wafer, characterized in that, It includes: A detection platform (10) for carrying the specimen to be measured, enabling the specimen to be measured to reciprocate along a preset direction under the drive of the detection platform (10); An adjusting unit (20) for controlling the specimen to be measured to rotate a set angle around its own axis; A sampling unit (30) for sampling a number of first sampling points on the specimen to be measured at intervals. When the specimen to be measured moves below the sampling unit (30), the specimen to be measured can move relative to the sampling unit (30) along a first preset direction to determine the detection voltage of each first sampling point; after controlling the specimen to be measured to rotate the set angle by the adjusting unit (20), the specimen to be measured can move relative to the sampling unit (30) along a second preset direction opposite to the first preset direction, so that the sampling unit (30) samples a number of second sampling points on the specimen to be measured at intervals to determine the detection voltage of each second sampling point; A control module for 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 when determining the no-load voltage of the sampling unit (30); Based on the pre-established resistivity calculation formula, substituting the reference voltage of each sampling point into the resistivity calculation formula to obtain the resistivity of each sampling point.

9. An electronic device, characterized in that, It includes: A memory and a processor, the memory stores a computer program, and is characterized in that when the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions, characterized in that, the computer-executable instructions are used to cause a computer to execute the method according to any one of claims 1 to 7.

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