Silicon carbide sorting machine

Abstract

The silicon carbide sorting machine comprises a feeding unit, an edge searching and code scanning device, a surface type detection device, a resistivity detection device, a first defect detection device, a second defect detection device and a discharging unit, the feeding unit is used for storing and moving a wafer, and the edge searching and code scanning device is used for detecting the circle center of the wafer and the position of a positioning part; the wafer is adjusted according to the detection result, the wafer identifier in the positioning part of the adjusted wafer is read, the surface type detection device is used for detecting the thickness of the wafer, and the resistivity detection device is used for sampling the voltage of a sampling point of the wafer and determining the resistivity of the sampling point according to a resistivity calculation formula. The first defect detection device is used for detecting two surfaces of a wafer and determining a first defect of the wafer according to the result, the second defect detection device is used for detecting one surface of the wafer and determining a second defect of the wafer according to the result, and the discharging unit is used for packaging the detected wafer. The silicon carbide sorting machine can realize continuous and automatic necessary item detection.

Description

Technical Field

[0001] This application relates to the technical field of silicon carbide sorting, and in particular to a silicon carbide sorter. Background Art

[0002] Silicon carbide (SiC) wafers, as an important semiconductor material, are widely used in electronic devices under extreme working conditions such as high power, high frequency, and high temperature. In the production and manufacturing process of silicon carbide wafers, steps such as cutting, grinding, and polishing are included. However, due to the hard and brittle nature of silicon carbide materials and their extreme sensitivity to the processing environment, microcracks, edge defects, delamination, and even warping and other defects are easily generated during the grinding and polishing processes. These defects directly affect the yield of the wafers and the subsequent process performance. Therefore, during the wafer manufacturing process, it is necessary to comprehensively detect and grade the processed silicon carbide wafers to ensure product quality and process stability.

[0003] In the prior art, although the detection technologies for processed silicon carbide wafers are relatively mature, there are still the following deficiencies: the detection processes are scattered, and there is a lack of unified coordination among detection devices. Some detection devices and methods have low detection accuracy and low detection efficiency. There is no integrated, fully automated detection system with high detection efficiency and accuracy on the market that can continuously and automatically complete the necessary item detections. The current detection process often relies on the combined use of multiple devices, and the handling and detection of wafers require frequent manual intervention, which is not only complex and inefficient, but also has a certain risk of human error. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the purpose of this application is to provide a silicon carbide sorter that can continuously and automatically complete the necessary item detections for silicon carbide wafers.

[0005] To achieve the above purpose, this application adopts the following technical solutions: The present application provides a silicon carbide sorting machine, including a feeding unit, a wafer edge finding and bar code scanning device, a wafer surface profile detection device, a wafer resistivity detection device, a first defect detection device, a second defect detection device, and a discharging unit. The feeding unit is used for storing and moving wafers. The wafer edge finding and bar code scanning device is used for detecting the positions of the center of the wafer and the positioning part, adjusting the wafer according to the detection results, and reading the wafer identification in the positioning part of the adjusted wafer. The wafer surface profile detection device is used for detecting the thickness of the wafer. The wafer resistivity detection device is used for detecting the resistivity of a plurality of sampling points in the wafer. The first defect detection device is used for detecting two surfaces of the wafer and determining a first type of defect of the wafer according to the detection results. The first type of defect includes at least one of micro holes and unremoved materials. The second defect detection device is used for detecting one surface of the wafer and determining a second type of defect of the wafer according to the detection results. The second type of defect includes at least one of chipping, crack, peeling trace, and phase change. The discharging unit is used for packaging the detected wafers. Among them, the feeding unit, the wafer edge finding and bar code scanning device, the wafer surface profile detection device, and the wafer resistivity detection device surround to form a first detection area. A first manipulator assembly is arranged in the first detection area. The first manipulator assembly is used for sequentially transporting wafers along the direction from the feeding unit, the wafer edge finding and bar code scanning device, the wafer surface profile detection device to the wafer resistivity detection device. The wafer resistivity detection device, the first defect detection device, the second defect detection device, and the discharging unit surround to form a second detection area. A second manipulator assembly is arranged in the second detection area. The second manipulator assembly is used for sequentially transporting wafers along the direction of the wafer resistivity detection device, the first defect detection device, the second defect detection device, and the discharging unit.

[0006] Further, the edge finding and bar code scanning device includes a wafer calibrator, a moving mechanism, and a photographing and bar code reading mechanism. A calibration station for placing the wafer is formed in the wafer calibrator. The wafer calibrator can detect the positions of the center of the wafer and the positioning part, and adjust the wafer according to the detection results. The moving mechanism has at least two degrees of freedom of movement on a horizontal plane. At least a part of the photographing and bar code reading mechanism is connected to the moving mechanism and can move under the action of the moving mechanism. The photographing and bar code reading mechanism is used for photographing and reading the wafer identification in the positioning part.

[0007] Further, the wafer calibrator includes a detection unit and an adjustment platform. The adjustment platform is used for supporting the wafer to keep the wafer in the calibration station. The detection unit is used for detecting the positions of the center of the wafer and the positioning part, and driving the adjustment platform according to the detection results to make the center coincide with the marked point in the calibration station and the positioning part face the set direction. The photographing and bar code reading mechanism includes a camera and a bar code reader. The camera is installed on the moving mechanism and can move under the drive of the moving mechanism to make the shooting angle of the camera focus on the positioning part. The camera is used for photographing the wafer identification located at the positioning part. The bar code reader can read the wafer identification.

[0008] Furthermore, the wafer edge finding and code scanning device further includes a processing module, which is electrically connected to the detection unit. The detection unit is also used for sampling the size, edge position and relative angle of the wafer. Among them, a reference direction is set at the calibration station, and the relative angle is the angle difference between the reference direction and the set direction. The processing module can generate the edge data of the wafer according to the sampling results of the detection unit; The processing module can also locate the wafer identification, the center of the wafer and the position of the positioning part based on the image captured by the camera to obtain the position data, fit the edge data with the positioning data, and compare the fitting result with the preset standard data to determine the accuracy of the wafer identification.

[0009] Furthermore, the moving mechanism includes a mounting platform, a first moving component and a second moving component. The first moving component is mounted on the mounting platform and can drive the second moving component to move along a first direction. The second moving component is mounted on the first moving component and can drive the camera to move along a second direction. The first direction is different from the second direction.

[0010] Furthermore, the shooting and code reading mechanism further includes a camera adjustment plate, which is connected to the second moving component, and the camera is mounted on the camera adjustment plate.

[0011] Furthermore, the wafer resistivity detection device is used to drive the wafer to move along a first preset direction and sample the voltages of several first sampling points on the wafer at intervals. The wafer resistivity detection device is also used to drive the wafer to rotate a set angle and move along a second preset direction, so that the wafer resistivity detection device samples several second sampling points on the wafer at intervals, and determines the resistivity of each sampling point according to the resistivity calculation formula. The first preset direction is opposite to the second preset direction.

[0012] Furthermore, the wafer resistivity detection device includes a detection platform, an adjustment unit, a sampling unit and a control module. The detection platform is used to carry the wafer so that the wafer can reciprocate under the drive of the detection platform; the sampling unit is used to sample several first sampling points on the wafer at intervals. When the wafer moves below the sampling unit, the wafer can move relative to the sampling unit along the first preset direction to determine the detection voltage of each first sampling point; the adjustment unit is used to drive the wafer to rotate a set angle. After controlling the wafer to rotate a set angle through the adjustment unit, the wafer can move relative to the sampling unit along the second preset direction under the action of the detection platform, so that the sampling unit samples several second sampling points on the wafer at intervals to determine the detection voltage of each second sampling point; the control module is used to 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 when the no-load voltage of the sampling unit is determined, and obtain the resistivity of each sampling point based on the resistivity calculation formula.

[0013] Further, the wafer surface profile detection device includes a fixed platform, a control platform, and a sensor unit. The control platform is mounted on the fixed platform and is used to fix the wafer. The control platform can also move relative to the fixed platform. The sensor unit is fixed relative to the fixed platform and is distributed on both the upper and lower sides of the control platform. The sensor unit is used to detect the thickness of the wafer.

[0014] Further, the control platform has at least two degrees of freedom of movement in the horizontal direction. When the control platform drives the wafer to move along one degree of freedom of movement, the sensor unit forms a first scanning path on the wafer. When the control platform drives the wafer to move along another degree of freedom of movement, the sensor unit forms a second scanning path on the wafer.

[0015] The silicon carbide sorter provided by this application integrates an edge-finding and barcode scanning device, a surface profile detection device, a resistivity detection device, and a defect detection device, and combines the coordinated transportation of the manipulator assembly, enabling the silicon wafer to complete multiple key detection items including position calibration, wafer identification recognition, surface profile detection, resistivity measurement, and defect detection in sequence without manual intervention, realizing the function of continuously and automatically completing the necessary item detection required for silicon carbide wafers. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the silicon carbide sorter in the embodiment of this application; Figure 2 is a top view of the silicon carbide sorter in the embodiment of this application; Figure 3 is a schematic structural diagram of the wafer edge-finding and barcode scanning device in the embodiment of this application; Figure 4 is Figure 3 an enlarged view of part A of Figure 5 is a schematic diagram of the first shooting angle of the wafer edge-finding and barcode scanning device in the embodiment of this application; Figure 6 is a schematic diagram of the second shooting angle of the wafer edge-finding and barcode scanning device in the embodiment of this application; Figure 7 is Figure 6 an enlarged view of part B of Figure 8 is a schematic structural diagram of the wafer surface profile detection device in the embodiment of this application; Figure 9 is a schematic diagram of the path of surface profile detection in the embodiment of this application; Figure 10 is a schematic structural diagram of the device for detecting the resistivity of the wafer in the embodiment of this application; Figure 11Schematic structural diagram of a wafer resistivity detection device from another angle in the embodiment of the present application; Figure 12 Schematic diagram of several sampling points in the embodiment of the present application; Figure 13 Schematic structural diagram of a first defect detection device in the embodiment of the present application; Figure 14 Schematic structural diagram of a second defect detection device in the embodiment of the present application.

[0017] Reference numerals: 100, silicon carbide sorter; 10, loading unit; 20, wafer edge finding and bar code scanning device; 21, support platform; 22, wafer calibrator; 221, detection unit; 222, adjustment platform; 23, moving mechanism; 231, mounting platform; 232, first moving component; 2321, first guide rail; 2322, first driving unit; 233, second moving component; 2331, second guide rail; 2332, second driving unit; 24, photographing and bar code reading mechanism; 241, camera; 242, bar code reader; 243, camera adjustment; 30, wafer surface profile detection device; 31, fixed platform; 311, linear guide rail; 32, control platform; 33, sensor unit; 40, wafer resistivity detection device; 41, detection platform; 411, silicon carbide bottom plate; 412, lead screw module; 42, adjustment unit; 421, cylinder; 422, ceramic suction cup; 423, rotation driving component; 43, sampling unit; 50, first defect detection device; 51, first bottom plate; 52, first defect detection component; 521, first support frame; 522, first detection camera; 523, first displacement platform; 524, first detection light source; 60, second defect detection device; 61, second bottom plate; 62, second defect detection component; 621, second support frame; 622, second detection camera; 623, second displacement platform; 624, second detection light source. Detailed implementation manners

[0018] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the specific embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present 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 among the components provided in the above embodiments are the same, this 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 form of limitation on the present invention.

[0020] As Figure 1 shown, the present application provides a silicon carbide sorter 100. To clearly illustrate the technical solution of the present invention, the up-down, left-right, front-back directions as shown in Figure 1 are also defined as the up-down, left-right, front-back directions of the silicon carbide sorter 100. In the description of the present application, the width direction of the silicon carbide sorter is the Figure 1 left-right direction as shown, the height direction of the silicon carbide sorter is the Figure 1 up-down direction as shown, and the length direction of the silicon carbide sorter is the Figure 1 front-back direction as shown.

[0021] The present application provides a silicon carbide sorter 100. As Figure 1 shown, as an implementation, the silicon carbide sorter 100 includes a loading unit 10, a wafer edge finding and bar code scanning device 20, a wafer surface profile detection device 30, a wafer resistivity detection device 40, a first defect detection device 50, a second defect detection device 60, and a unloading unit 70.

[0022] The loading unit 10 is used to store and move wafers.

[0023] The wafer edge finding and bar code scanning device 20 is used to detect the center of the wafer and the position of the positioning part, adjust the wafer according to the detection result, and read the wafer identification in the positioning part of the adjusted wafer.

[0024] The wafer surface profile detection device 30 is used to detect the thickness of the wafer.

[0025] The wafer resistivity detection device 40 is used to drive the wafer to move along a first preset direction, and sample the voltages of a number of first sampling points on the wafer at intervals. The wafer resistivity detection device 40 is also used to drive the wafer to rotate a set angle and move along a second preset direction, so that the wafer resistivity detection device 40 samples a number of second sampling points on the wafer at intervals, and determines the resistivity of each sampling point according to the resistivity calculation formula. The first preset direction is opposite to the second preset direction.

[0026] The first defect detection device 50 is configured to detect two surfaces of the wafer and determine the first type of defects of the wafer according to the detection results, where the first type of defects includes at least one of micro holes and unremoved materials.

[0027] The second defect detection device 60 is configured to detect one surface of the wafer and determine the second type of defects of the wafer according to the detection results, where the second type of defects includes at least one of chipping, crack, peeling trace, and phase change.

[0028] The blanking unit 70 is configured to package the wafer after detection.

[0029] In the embodiment of the present application, the wafer is calibrated for the center and positioning information through the wafer edge finding and bar code scanning device 20, and the identification reading of the wafer identification is completed. Subsequently, the wafer enters the wafer surface profile detection device 30, the resistivity detection device 40 of the wafer, the first defect detection device 50, and the second defect detection device 60 in sequence, completing the full-automatic sampling and judgment of the thickness, electrical characteristics, and surface defects of the wafer. Finally, the wafers are classified and stored according to the detection results.

[0030] Through the above settings, the silicon carbide sorting machine 100 can continuously complete the detection of multiple key items including wafer position calibration, wafer identification recognition, surface profile detection, resistivity detection, and defect detection without manual intervention, realizing the automatic processing of the whole process from wafer feeding to blanking, and significantly improving the detection efficiency and accuracy.

[0031] As Figure 2 shown, as an implementation, the loading unit 10, the wafer edge finding and bar code scanning device 20, the wafer surface profile detection device 30, and the resistivity detection device 40 of the wafer surround to form a first detection area 101. A first robot component 80 is arranged in the first detection area 101, and the first robot component 80 is configured to sequentially transport the wafer along the directions of the loading unit 10, the wafer edge finding and bar code scanning device 20, the wafer surface profile detection device 30, and the resistivity detection device 40 of the wafer. Further, the resistivity detection device 40 of the wafer, the first defect detection device 50, the second defect detection device 60, and the blanking unit 70 surround to form a second detection area 102. A second robot component 90 is arranged in the second detection area 102, and the second robot component 90 is configured to sequentially transport the wafer along the directions of the resistivity detection device 40 of the wafer, the first defect detection device 50, the second defect detection device 60, and the blanking unit 70.

[0032] With the above settings, the structural layout between the various modules of the silicon carbide sorter 100 is compact. With the above structural layout, the internal module arrangement of the silicon carbide sorter 100 has a clear functional partition, effectively improving the overall space utilization rate of the silicon carbide sorter 100 and the coherence of the detection process, and enhancing the detection efficiency of the wafers.

[0033] As Figure 3 shown, as an implementation, the wafer edge finding and bar code scanning device 20 includes a support platform 21, a wafer calibrator 22, a moving mechanism 23, and a photographing and bar code reading mechanism 24. The wafer calibrator 22 is installed on the support platform 21. A calibration station for placing the wafer is formed in the wafer calibrator 22. The wafer calibrator 22 can detect the position of the center of the wafer and the positioning portion, and adjust the wafer according to the detection results. The moving mechanism 23 is installed on the support platform 21. The moving mechanism 23 is used to drive the photographing and bar code reading mechanism 24 to move. The moving mechanism 23 has at least two degrees of freedom of movement in the horizontal plane. At least a part of the photographing and bar code reading mechanism 24 is connected to the moving mechanism 23 and can move under the action of the moving mechanism 23. The photographing and bar code reading mechanism 24 is used to photograph and read the wafer identification in the positioning portion.

[0034] As Figure 4 and 5 shown, as an implementation, the wafer calibrator 22 includes a detection unit 221 and an adjustment platform 222. The adjustment platform 222 is located below the calibration station and is used to support the wafer to keep the wafer in the calibration station. The detection unit 221 is located above the calibration station. The detection unit 221 is used to detect the center of the wafer and the positioning portion. Among them, the outer edge of the wafer has a wafer flat edge (also known as a wafer flat groove, a wafer groove, a wafer V-groove). The wafer flat edge can be used as the positioning portion of the wafer to determine the direction of the wafer.

[0035] In the specific detection process, the detection unit 221 detects the wafer placed on the adjustment platform 222, detects the center coordinate of the wafer and the position of the positioning portion. The detection unit 221 compares the collected center coordinate of the wafer with the coordinate of the marked point in the calibration station to determine the coordinate deviation. The detection unit 221 compares the collected orientation of the positioning portion with the set direction to determine the direction deviation. Among them, a reference direction is set in the calibration station or the detection unit 221. In the implementation manner of the present application, the set direction means that the positioning portion forms a 90° angle with the reference direction in the horizontal direction. The detection unit 221 drives the adjustment platform 222 according to the coordinate deviation and the direction deviation, so as to perform translation and rotation adjustment on the wafer, so that the center coincides with the marked point in the calibration station and the positioning portion faces the set direction.

[0036] Exemplarily, the detection unit 221 first acquires the wafer image. Through an algorithm, it determines that the center coordinates of the wafer are (100.5, 200.3) pixels, while the position of the marking point in the calibration station is (100, 200) pixels, and there is a deviation of 5° between the positioning part and the set direction. The detection unit 221 feeds back these deviation data to the adjustment platform 222. Subsequently, the adjustment platform 222 performs translation and rotation adjustments on the wafer until the center of the wafer accurately moves to the position of (100, 200) pixels, and at the same time rotates the positioning part by 5° to make it consistent with the set direction.

[0037] In some alternative embodiments, the adjustment platform 222 is a circular platform and can rotate along its circumferential direction to adjust the direction of the wafer so that the positioning part of the wafer faces the set direction. When the wafer is placed in the calibration station, the center of the wafer needs to coincide with the marking point of the calibration station. The adjustment platform 222 has a degree of freedom of movement in the horizontal direction. If the center of the wafer does not coincide with the marking point of the calibration station, the adjustment platform 222 can also be driven to move in the horizontal direction to make the center of the wafer coincide with the marking point of the calibration station.

[0038] In some alternative embodiments, a processor unit is configured in the wafer calibrator 22. The processor unit is electrically connected to the detection unit 221 and the adjustment platform 222 respectively. The detection unit 221 is only used to acquire the center coordinates of the wafer and the position of the positioning part of the wafer, and transmits the acquired data to the processor unit. The processor unit performs a specific comparison process and generates a signal representing the comparison result, and controls the adjustment platform 222 through the signal to perform translation and rotation adjustments on the wafer, so that the center coincides with the marking point in the calibration station and the positioning part faces the set direction.

[0039] The moving mechanism 23 is installed on the support platform 21, and the moving mechanism 23 has degrees of freedom of movement in at least two directions on the horizontal plane.

[0040] Exemplarily, the moving mechanism 23 can at least move along a first direction and a second direction, where the first direction and the second direction refer to two independent and mutually orthogonal movement directions on the horizontal plane.

[0041] The photographing and code reading mechanism 24 includes a camera 241 and a code reader 242. The camera 241 is installed on the moving mechanism 23 and can move under the drive of the moving mechanism 23 to focus the shooting angle of the camera 241 on the positioning part of the wafer adjusted in the calibration station and photograph the wafer identification located at the positioning part. The code reader 242 can read the wafer identification of the wafer. Among them, the wafer identification is a laser engraving code engraved on the wafer.

[0042] With the above settings, while the wafer edge finding and code scanning device 20 performs edge finding and positioning on the wafer, it detects the wafer identification of the wafer, realizes the detection of the accuracy of the wafer identification, and improves the production efficiency of the wafer.

[0043] To clearly illustrate the technical solution of this application, the wafer is divided into a reference wafer and a wafer to be tested. The shooting angle position (i.e., the focal point position) of the camera 241 is determined through the reference wafer, and the shooting angle position of the camera 241 is kept unchanged. Then, the wafer identification of the wafer to be tested is detected.

[0044] Specifically, the first manipulator assembly 80 places the reference wafer as a reference on the adjustment platform 222. The detection unit 221 detects the reference wafer located on the adjustment platform 222 to determine the center of the reference wafer and the position of the positioning portion. The adjustment platform 222 adjusts the reference wafer based on the detection result of the detection unit 221 so that the positioning portion of the reference wafer faces the set direction. The adjustment platform 222 adjusts the reference wafer based on the detection result of the detection unit 221 so that the center of the reference wafer coincides with the marking point in the calibration station. The moving mechanism 23 adjusts the camera 241 so that the shooting angle of the camera 241 focuses on the positioning portion of the reference wafer, and captures the wafer identification located at the positioning portion of the reference wafer. When the shooting angle of the camera 241 focuses on the wafer identification of the reference wafer, the shooting angle of the camera 241 remains fixed. The code reader 242 reads the wafer identification of the reference wafer.

[0045] In the embodiment of this application, the wafer edge finding and code scanning device 20 further includes a processing module, and the processing module is electrically connected to the camera 241. The processing module is used to obtain the images captured by the camera 241, and these images contain the position information of multiple parts on the reference wafer. Among them, the multiple parts include the wafer identification of the reference wafer, the center of the reference wafer, and the positioning portion of the reference wafer. The processing module can set the position deviation range according to the wafer identification of the reference wafer.

[0046] Further, replace the reference wafer with the wafer to be tested. If the center of the wafer to be tested coincides with the marking point in the calibration station and the positioning portion of the wafer to be tested faces the set direction, the camera 241 captures the wafer identification at the positioning portion of the wafer to be tested. Determine whether the position of the wafer identification of the wafer to be tested is within the position deviation range. If the position of the wafer identification of the wafer to be tested is within the position deviation range, the accuracy of the wafer identification of the wafer to be tested is detected; if the position of the wafer identification of the wafer to be tested is outside the position deviation range, the wafer to be tested is calibrated as a defective wafer.

[0047] With the above settings, it is possible to effectively detect the position and accuracy of the wafer identification of the wafer to be tested, which helps to ensure the accuracy and consistency of the subsequent detection process.

[0048] As an implementation, the detection unit 221 is further configured to sample the size, position, and relative angle of the edge of the wafer to be measured, where the relative angle is the angle difference between the reference direction and the set direction. The processing module is configured to generate edge data of the wafer according to the sampling results of the detection unit 221. The processing module is further configured to locate the wafer identification, the center of the circle, and the position of the positioning portion of the wafer to obtain positioning data, and fit the edge data with the positioning data, and compare the fitting result with the set standard data to determine the accuracy of the wafer identification.

[0049] With the above settings, the wafer edge finding and code scanning device 20 integrates the functions of wafer edge finding and positioning and detecting the processing accuracy of the wafer identification, improves the detection efficiency of the wafer quality, and reduces the detection cost.

[0050] Further, the processing module is further configured to adjust the gray value of the image so that the difference between the gray value of the wafer identification of the wafer and the gray value of the image background is greater than the set gray value threshold.

[0051] Exemplarily, the gray value of the wafer identification of the wafer to be measured is adjusted to 100, and the gray value of the background is adjusted to 50.

[0052] With the above settings, the contrast of the wafer identification in the image is improved, and the subsequent code reading process can more accurately identify and locate the wafer identification of the wafer, improving the detection accuracy of the wafer identification of the wafer.

[0053] As Figure 6 and Figure 7 shown, as an implementation, the moving mechanism 23 includes a mounting platform 231, a first moving component 232, and a second moving component 233. The mounting platform 231 is fixed to the support platform 21 to support the moving mechanism 23 and ensure the stability of subsequent components. The first moving component 232 is mounted on the mounting platform 231 and can drive the second moving component 233 to move in the first direction. The camera 241 is mounted on the second moving component 233. The second moving component 233 is mounted on the first moving component 232, and the second moving component 233 can drive the camera 241 to move in the second direction.

[0054] Further, the first moving component 232 includes a first guide rail 2321 and a first driving unit 2322. The second moving component 233 includes a second guide rail 2331 and a second driving unit 2332. The first guide rail 2321 is fixed to the mounting platform 231. The second guide rail 2331 can move relative to the first guide rail 2321 in the first direction under the action of the first driving unit 2322. The camera 241 can move relative to the second guide rail 2331 in the second direction under the action of the second driving unit 2332.

[0055] Specifically, by driving the second guide rail 2331 to move relative to the first guide rail 2321 in the first direction through the first driving unit 2322, the continuous and controllable movement of the second guide rail 2331 in the first direction is achieved, thereby ensuring the positioning accuracy of the camera 241 in the first direction. By driving the camera 241 to move relative to the second guide rail 2331 in the second direction through the second driving unit 2332, the precise movement of the camera 241 in the second direction is realized, enabling the camera 241 to have degrees of freedom of movement in at least two directions on the horizontal plane and reach any predetermined position within the horizontal plane. Furthermore, it can ensure that the target area (such as the wafer identification of the reference wafer) is always within the field of view of the camera 241.

[0056] Through the above settings, the moving mechanism 23 has the positioning ability of high precision and multiple degrees of freedom, providing a stable and reliable moving platform for the camera 241, and ensuring that the camera 241 can always accurately focus on the target area during the scanning or edge-finding process.

[0057] As Figure 5 shown, further, the shooting and code reading mechanism 24 further includes a camera adjustment plate 243. The camera adjustment plate 243 is connected to the second moving component 233, and the camera 241 is installed on the camera adjustment plate 243. The camera adjustment plate 243 serves to connect and fix the camera 241, and at the same time, the camera adjustment plate 243 is also used to adjust the distance between the camera 241 and the wafer.

[0058] As Figure 8 shown, as a realization method, the wafer surface profile detection device 30 includes a fixed platform 31, a control platform 32, and a sensor unit 33. The control platform 32 is installed on the fixed platform 31 for fixing the wafer. A linear guide rail 311 is provided on the fixed platform 31, and the control platform 32 is installed on the fixed platform 31 through the linear guide rail 311. The control platform 32 can also move relative to the fixed platform 31. The sensor unit 33 is relatively fixed to the fixed platform 31 and is distributed on the upper and lower sides of the control platform 32. The sensor unit 33 is used to detect the thickness of the wafer.

[0059] Furthermore, the control platform 32 has at least two degrees of freedom of movement in the horizontal direction. When the control platform 32 drives the wafer to move along one degree of freedom of movement, the sensor unit 33 forms a first scanning path on the wafer. When the control platform 32 drives the wafer to move along another degree of freedom of movement, the sensor unit 33 forms a second scanning path on the wafer.

[0060] Exemplarily, by scanning the surface of the wafer with the sensor unit 33 to form as Figure 9The multiple scanning paths shown, each scanning path having multiple detection points, identify the wafer thickness of each detection point in each scanning path, and determine the average thickness of the wafer based on the wafer thickness of each detection point in the multiple scanning paths. Optionally, if the wafer thickness of any detection point in the multiple scanning paths exceeds a preset thickness threshold, the wafer can also be marked as a defective wafer.

[0061] Through the above settings, the wafer surface profile detection device 30 can, in cooperation with the multi-degree-of-freedom movement of the control platform 32, achieve multi-point thickness scanning of the wafer on different paths, thereby obtaining complete data of the wafer surface profile, improving the detection coverage and accuracy, and meeting the high-precision detection requirements for geometric parameters such as wafer flatness and warpage.

[0062] As Figure 10 and Figure 11 shown, as an implementation manner, the wafer resistivity detection device 40 includes: a detection platform 41, an adjustment unit 42, a sampling unit 43, and a control module (not shown in the figure), where: The detection platform 41 is used to carry the wafer, so that the wafer can reciprocate along a preset direction under the drive of the detection platform 41; The adjustment unit 42 is used to control the wafer to rotate a set angle around its own axis; The sampling unit 43 is used to sample a number of first sampling points on the wafer at intervals. When the wafer moves below the sampling unit 43, the wafer can move relative to the sampling unit 43 along a first preset direction to determine the detection voltage of each first sampling point; after controlling the wafer to rotate a set angle through the adjustment device, the wafer can move relative to the sampling unit 43 along a second preset direction, so that the sampling unit 43 samples a number of second sampling points on the wafer 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 43, 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 a 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.

[0063] As an implementation manner, the detection platform 41 includes a silicon carbide bottom plate 411 and a lead screw module 412. The silicon carbide bottom plate 411 is used to carry the wafer, and the lead screw module 412 is connected to the silicon carbide bottom plate 411. The moving direction of the silicon carbide bottom plate 411 is determined by the lead screw module 412 to ensure that the wafer can reciprocate along a preset direction under the drive of the silicon carbide bottom plate 411.

[0064] During the detection process, the silicon carbide base plate 411 is driven by the lead screw module 412 to move the wafer along the first preset direction to below the sampling unit 43. At this time, the sampling unit 43 collects the voltage of the first sampling point. After the collection is completed, the adjustment unit 42 is activated to lift the wafer to separate it from the silicon carbide base plate 411, and drive the wafer to rotate by a set angle. Then, the adjustment unit 42 descends to place the wafer back on the silicon carbide base plate 411. At this time, the silicon carbide base plate 411 moves along the second preset direction, and the sampling unit 43 samples the voltage of the second sampling point.

[0065] After the sampling unit 43 completes the sampling of the wafer along the first preset direction, when the wafer is driven to rotate by a set angle (such as 15°), the next round of voltage sampling is ready. When the wafer finishes rotating, the silicon carbide base plate 411 will drive the wafer to move smoothly along the second preset direction (the second preset direction is opposite to the first preset direction). Among them, Figure 12 the numbers represent the voltage sampling path. The wafer 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 43 can measure the voltage of the sampling point at the new position in the shortest time. Through this setting, the sampling unit 43 can achieve higher sampling efficiency within the unit sampling time.

[0066] In the embodiment of the present application, the silicon carbide base plate 411 is driven by the lead screw module 412 to make the wafer perform a linear reciprocating motion along the preset direction on the detection platform 41, significantly improving the detection efficiency.

[0067] Furthermore, the adjustment unit 42 includes a cylinder 421, a ceramic suction cup 422, and a rotation drive assembly 423. The adjustment unit 42 is used to control the wafer to rotate by a set angle around its axis. During the working process of the adjustment unit 42, first, the cylinder 421 lifts the ceramic suction cup 422 and the wafer to separate them from the detection platform 41. Subsequently, the rotation drive assembly 423 drives the ceramic suction cup 422 and the wafer to rotate by a set angle around the central axis. After the rotation is completed, the cylinder 21 descends to place the wafer back on the silicon carbide base plate 411. At this time, the detection platform 41 moves along the second preset direction, and the sampling unit 43 samples the voltage of the second sampling point.

[0068] In the embodiment of the present application, through the structural cooperation of each part of the adjustment unit 42, the precise rotation of the adjustment unit 42 is realized, laying a foundation for the multi-angle and multi-direction detection of the wafer.

[0069] Further, the sampling unit 43 is configured to sample a plurality of first sampling points and second sampling points on the wafer at intervals. During the sampling process, when the detection platform 41 drives the wafer to move under the resistivity probe 31, the control module controls the sampling unit to start voltage acquisition at a distance of 1 mm from the sampling point and stop acquisition after moving more than 1 mm. 20 sets of voltage data are collected for each sampling point, and the control module calculates the average value as the detection voltage and deducts the no-load voltage (the output voltage when the resistivity probe is suspended) in real time.

[0070] In the embodiment of the present application, through the precise control of the control module, two-way sampling of the wafer is achieved. In this embodiment, the voltage sampling improves the measurement accuracy through the average value method, solves the problems of few sampling points and low detection efficiency in the prior art, and realizes multi-point sampling and high-precision detection.

[0071] Further, the control module includes a host computer and a PLC control system. The host computer is configured to receive and process the voltage data collected by the sampling unit 43, and the PLC control system is configured to control the detection platform 41, the adjustment unit 42, and the action of the sampling unit 43. The PLC control system uploads the collected voltage data to the host computer, and the host computer is built with a calibration algorithm module, which is configured to 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 when the no-load voltage of the sampling unit 43 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.

[0072] In the embodiment of the present application, through the automatic calculation function of the control module, the problems of complex resistivity calculation and low efficiency in the prior art are solved, and the rapid and accurate calculation of resistivity is realized.

[0073] Such as Figure 13As shown, as an implementation method, the first defect detection device 50 includes a first base plate 51, a first defect detection assembly 52, and the first defect detection assembly 52 includes a first support frame 521, a first detection camera 522, a first displacement platform 523, and a first detection light source 524. The first base plate 51 is used to fix the first defect detection device 50. Due to the needs of actual use and installation process, along the height direction of the silicon carbide sorting machine 100, the first defect detection assembly 52 is basically symmetrically arranged on the upper and lower sides of the first base plate 51, which is used to simultaneously shoot and image both sides of the wafer. The first support frame 521 includes a longitudinal beam and a cross beam. The first support frame 521 is installed on the first base plate 51 in a "冂" shape. The first displacement platform 523 is installed on the cross beam of the first support frame 521, which is used to drive the first detection camera 522 to move. The first detection camera 522 is installed on the first displacement platform for shooting wafer images. The first detection light source 524 is installed on the first detection camera 522 to supplement light, so that the wafer image obtained by the first detection camera 522 is clearer.

[0074] like Figure 14 As shown, as an implementation method, the second defect detection device 60 includes a second base plate 61, a second defect detection assembly 62, and the second defect detection assembly 62 includes a second support frame 621, a second detection camera 622, a second displacement platform 623, and a second detection light source 624. The second base plate 61 is used to fix the second defect detection device 60. Along the height direction of the silicon carbide sorting machine 100, the second defect detection assembly 62 is arranged above the second base plate 61 for photographing and imaging the wafer. The second support frame 621 includes a longitudinal beam and a cross beam. The second support frame 621 is installed on the second base plate 61 in a "冂" shape. The second displacement platform 623 is installed on the cross beam of the second support frame 621 to drive the second detection camera 622 to move. The second detection camera 622 is installed on the second displacement platform 623 to shoot the wafer image. The second detection light source 624 is installed on the second base plate 61 to supplement the light so that the wafer image obtained by the second detection camera 622 is clearer.

[0075] It should be noted that, since the second defect detection device 60 can detect the result by photographing one surface of the wafer, in order to image once and improve the detection efficiency, the imaging field of the second detection camera 622 should be larger than the imaging field of the first detection camera 522, that is, the height of the longitudinal beam of the second support frame 621 is larger than the height of the longitudinal beam of the first support frame 521. In addition, the first defect detection device 50 requires a high-resolution camera to clearly capture the tiny defects on the wafer and improve the accuracy of defect detection.

[0076] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A silicon carbide separator (100), characterized in that, Including: A loading unit (10) for storing wafers; A wafer edge finding and code scanning device (20) for detecting the positions of the center of the wafer and the positioning part, adjusting the wafer according to the detection results, and reading the wafer identification in the positioning part of the adjusted wafer; A wafer surface profile detection device (30) for detecting the thickness of the wafer; A wafer resistivity detection device (40) for detecting the resistivity of a number of sampling points in the wafer; A first defect detection device (50) for detecting two surfaces of the wafer and determining a first type of defect of the wafer according to the detection results, the first type of defect including at least one of micro holes and unremoved materials; A second defect detection device (60) for detecting one surface of the wafer and determining a second type of defect of the wafer according to the detection results, the second type of defect including at least one of chipping, crack, peeling trace, and phase change; An unloading unit (70) for packaging the detected wafers; Wherein, the loading unit (10), the wafer edge finding and code scanning device (20), the wafer surface profile detection device (30), and the wafer resistivity detection device (40) surround to form a first detection area, and a first manipulator assembly is arranged in the first detection area, and the first manipulator assembly is used to transport the wafer in the direction from the loading unit, the wafer edge finding and code scanning device (20), the wafer surface profile detection device (30) to the wafer resistivity detection device (40); the wafer resistivity detection device (40), the first defect detection device (50), the second defect detection device (60), and the unloading unit (70) surround to form a second detection area, and a second manipulator assembly is arranged in the second detection area, and the second manipulator assembly is used to transport the wafer in the direction of the wafer resistivity detection device (40), the first defect detection device (50), the second defect detection device (60), and the unloading unit (70).

2. The silicon carbide sorting machine according to claim 1, wherein The edge finding and code scanning device (20) includes a wafer calibrator (22), a moving mechanism (23), and a photographing and code reading mechanism (24). A calibration station for placing the wafer is formed in the wafer calibrator (22). The wafer calibrator can detect the positions of the center of the wafer and the positioning part and adjust the wafer according to the detection results. The moving mechanism (23) has at least two degrees of freedom of movement in the horizontal plane. At least a part of the photographing and code reading mechanism is connected to the moving mechanism and can move under the action of the moving mechanism. The photographing and code reading mechanism is used to photograph and read the wafer identification in the positioning part.

3. The silicon carbide sorting machine according to claim 2, wherein The wafer calibrator (22) includes a detection unit (221) and an adjustment platform (222). The adjustment platform (222) is used to support the wafer and keep the wafer at the calibration station. The detection unit (221) is used to detect the positions of the center of the wafer and the positioning portion, and drive the adjustment platform according to the detection results to make the center of the wafer coincide with the marking point at the calibration station, and the positioning portion faces the set direction. The photographing and code reading mechanism (24) includes a camera (241) and a code reader (242). The camera (241) is installed on the moving mechanism (23) and can move under the drive of the moving mechanism (23) to make the photographing angle of view of the camera (241) focus on the positioning portion. The camera (241) is used to photograph the wafer identification at the positioning portion, and the code reader (242) can read the wafer identification.

4. The silicon carbide sorting machine according to claim 3, characterized in that The wafer edge finding and code scanning device (20) further includes a processing module, which is electrically connected to the detection unit (221). The detection unit (221) is further used to sample the size, edge position and relative angle of the wafer. Among them, a reference direction is set at the calibration station, and the relative angle is the angle difference between the reference direction and the set direction. The processing module can generate the edge data of the wafer according to the sampling results of the detection unit (221); The processing module can also position the wafer identification, the center of the wafer and the position of the positioning portion based on the image photographed by the camera (241) to obtain position data, fit the edge data with the positioning data, and compare the fitting result with the preset standard data to determine the accuracy of the wafer identification.

5. The silicon carbide sorting machine according to claim 2, characterized in that The moving mechanism (23) includes a mounting platform (231), a first moving component (232) and a second moving component (233). The first moving component (232) is installed on the mounting platform (231) and can drive the second moving component (233) to move along a first direction. The second moving component (233) is installed on the first moving component (232) and can drive the camera (241) to move along a second direction. The first direction is different from the second direction.

6. The silicon carbide sorting machine according to claim 5, characterized in that The photographing and code reading mechanism (24) further includes a camera adjustment plate (243). The camera adjustment plate (243) is connected to the second moving component (233), and the camera (241) is installed on the camera adjustment plate (243).

7. The silicon carbide sorting machine according to claim 1, characterized in that The detection device (40) for the resistivity of the wafer is used to drive the wafer to move along a first preset direction, and intermittently sample the voltages of a plurality of first sampling points on the wafer. The detection device (40) for the resistivity of the wafer is further used to drive the wafer to rotate by a set angle and move along a second preset direction, so that the detection device (40) for the resistivity of the wafer intermittently samples a plurality of second sampling points on the wafer, and determines the resistivity of each of the sampling points according to the resistivity calculation formula. The first preset direction is opposite to the second preset direction.

8. The silicon carbide sorting machine according to claim 7, wherein The detection device (40) for the resistivity of the wafer includes a detection platform (41), an adjustment unit (42), a sampling unit (43) and a control module. The detection platform (41) is used to carry the wafer so that the wafer can reciprocate under the drive of the detection platform (41); the sampling unit (43) is used to intermittently sample a plurality of the first sampling points on the wafer. When the wafer moves below the sampling unit (43), the wafer can move relative to the sampling unit (43) along the first preset direction to determine the detection voltage of each of the first sampling points; the adjustment unit (42) is used to drive the wafer to rotate by a set angle. After the wafer is controlled by the adjustment unit (42) to rotate the set angle, the wafer can move relative to the sampling unit (43) along the second preset direction under the action of the detection platform (41), so that the sampling unit (43) intermittently samples a plurality of the second sampling points on the wafer to determine the detection voltage of each of the second sampling points; the control module is used to determine the reference voltage of each of the sampling points based on the difference between the detection voltage of each of the sampling points and the no-load voltage when the no-load voltage of the sampling unit (43) is determined, and obtain the resistivity of each of the sampling points based on the resistivity calculation formula.

9. The silicon carbide sorting machine according to claim 1, wherein The wafer surface profile detection device (30) includes a fixed platform (31), a control platform (32) and a sensor unit (33). The control platform (32) is installed on the fixed platform (31) and is used to fix the wafer. The control platform (32) can also move relative to the fixed platform (31). The sensor unit (33) is relatively fixed to the fixed platform (31) and is distributed on the upper and lower sides of the control platform (32). The sensor unit (33) is used to detect the thickness of the wafer.

10. The silicon carbide sorting machine according to claim 9, wherein The control platform (32) has at least two degrees of freedom of movement in the horizontal direction. When the control platform (32) drives the wafer to move along one of the degrees of freedom of movement, the sensor unit (33) forms a first scanning path on the wafer. When the control platform (32) drives the wafer to move along another degree of freedom of movement, the sensor unit (33) forms a second scanning path on the wafer.

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