Wafer edge scanning method and device

Abstract

The present application discloses a wafer edge-finding and scanning method and device, which includes: adjusting the center of the reference wafer and the position of the positioning part so that the center of the reference wafer coincides with the mark point in the calibration station, and the positioning part of the reference wafer faces the set direction; focusing the shooting angle on the positioning part of the reference wafer and fixing the shooting angle; shooting the wafer mark at the positioning part of the reference wafer, and setting the position deviation range based on the position of the wafer mark of the reference wafer; replacing the reference wafer with the wafer to be tested, adjusting the center of the wafer to be tested to coincide with the mark point, and the positioning part of the wafer to be tested to face the set direction; shooting the wafer mark at the positioning part of the wafer to be tested, and if the position of the wafer mark of the wafer to be tested is within the position deviation range, then the accuracy of the wafer mark of the wafer to be tested is detected. This method realizes the detection of the wafer mark accuracy while performing edge-finding and positioning on the wafer, thereby improving the production efficiency of the wafer.

Description

Technical Field

[0001] The present application relates to the field of silicon carbide sorting technology, and in particular to a wafer edge-finding and scanning method and device. Background Art

[0002] Silicon carbide (SiC) wafers, as an important semiconductor material, are widely used in electronic devices operating in extreme environments such as high power, high frequency, and high temperature. During wafer manufacturing and processing, sorting wafers based on size, shape, and quality is crucial for ensuring product quality. Therefore, wafer inspection is necessary to ensure the consistency and accuracy of each wafer.

[0003] In current production practices, each wafer is typically laser-engraved with a unique wafer identifier (laser code). These laser codes serve as identification and tracking tools during wafer sorting and inspection. However, existing technology is typically limited to simply scanning the laser code and transmitting its information to a host computer system to monitor the subsequent wafer processing flow. Detailed testing of the laser code's processing accuracy (i.e., whether the engraved laser code meets factory standards) is not performed. Adding a laser code processing accuracy inspection process would reduce wafer production efficiency. Summary of the Invention

[0004] In order to address the deficiencies of the prior art, the purpose of this application is to provide a wafer edge-finding and code-scanning method and device, which can perform edge-finding and positioning of the wafer and detect the processing accuracy of the wafer identification.

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

[0006] In a first aspect, the present application provides a wafer edge finding and code scanning method, the method comprising:

[0007] When the reference wafer is placed in the calibration station, the center of the reference wafer and the position of the positioning portion are adjusted so that the center of the reference wafer coincides with the mark point in the calibration station and the positioning portion of the reference wafer faces the set direction;

[0008] Focusing the shooting angle of view on the positioning portion of the reference wafer and fixing the shooting angle of view;

[0009] photographing a wafer mark located at a positioning portion of a reference wafer, and setting a position deviation range based on a position of the wafer mark of the reference wafer;

[0010] Replace the reference wafer with the wafer to be tested, adjust the center of the wafer to be tested to coincide with the mark point in the calibration station, and point the positioning portion of the wafer to be tested toward the set direction;

[0011] The wafer mark at the positioning portion of the wafer to be tested is photographed. If the position of the wafer mark of the wafer to be tested is within the position deviation range, the accuracy of the wafer mark of the wafer to be tested is tested.

[0012] Furthermore, the method further comprises:

[0013] If the position of the wafer mark of the wafer to be tested is outside the position deviation range, it is determined that the wafer to be tested is a defective wafer.

[0014] Furthermore, the wafer marking accuracy of the wafer to be tested is tested, including:

[0015] Based on the captured image, the center of the wafer to be tested, the positioning portion, and the position of the wafer mark are located to obtain positioning data;

[0016] Sampling the size, edge position and relative angle of the wafer to be measured to obtain edge data, wherein the calibration station is set with a reference direction, and the relative angle is the angle difference between the reference direction and the set direction;

[0017] Fit the edge data with the positioning data, and compare the fitting results with the preset standard data to determine the accuracy of the wafer to be tested.

[0018] Furthermore, before locating the center of the wafer to be measured, the positioning portion, and the wafer mark based on the captured image, the following steps are included:

[0019] Adjust the grayscale value of the captured image so that the difference between the grayscale value of the wafer mark of the wafer to be tested and the grayscale value of the image background is greater than the set grayscale value threshold.

[0020] Furthermore, the edge data is fitted with the positioning data, and the fitting result is compared with the preset standard data to determine the accuracy of the wafer to be tested, including:

[0021] Draw a fitting curve representing the wafer to be tested based on edge data and positioning data;

[0022] Compare the fitting curve with the standard data to obtain the fitting degree of the wafer to be tested;

[0023] If the degree of fit is outside a preset threshold range, the wafer to be tested is determined to be a defective wafer.

[0024] In a second aspect, the present application further provides a wafer edge-finding and code scanning device, which includes:

[0025] Support platform;

[0026] A wafer aligner is mounted on a support platform. A calibration station for placing wafers is formed in the wafer aligner. The wafer aligner includes a detection unit and an adjustment platform. The adjustment platform is used to support the wafer and keep the wafer in the calibration station. The detection unit is used to detect the center of the wafer and the position of the positioning part, and drive the adjustment platform based on the detection results to make the center of the wafer coincide with the mark point in the calibration station and the positioning part face the set direction.

[0027] A moving mechanism, the moving mechanism is installed on the supporting platform, and the moving mechanism has freedom of movement in at least two directions on the horizontal plane;

[0028] The shooting and code reading mechanism includes a camera and a code reader. The camera is installed on the moving mechanism and can move under the drive of the moving mechanism so that the camera's shooting angle is focused on the positioning part. The camera is used to shoot the wafer mark located at the positioning part, and the code reader can read the wafer mark.

[0029] Furthermore, the wafer edge-finding and scanning device further includes a processing module, which is electrically connected to the detection unit. The detection unit is further used to sample the size, edge position, and relative angle of the wafer. The calibration station is set with a reference direction, and the relative angle is the angle difference between the reference direction and the set direction. The processing module can generate edge data of the wafer based on the sampling results of the detection unit.

[0030] The processing module can also locate the wafer identification, center of the circle and the positioning part of the wafer based on the image taken by the camera to obtain positioning data, and fit the edge data with the positioning data, compare the fitting results with the preset standard data, and determine the accuracy of the wafer identification.

[0031] Furthermore, the moving mechanism includes a mounting platform, a first moving component and a second moving component. The mounting platform is fixed to the supporting platform. The first moving component is mounted on the mounting platform and can drive the second moving component to move in a first direction. The second moving component is mounted on the first moving component and can drive the camera to move in a second direction. The first direction is different from the second direction.

[0032] Furthermore, the first moving component includes a first guide rail and a first driving unit, and the second moving component includes a second guide rail and a second driving unit. The first guide rail is fixed to the mounting platform, and the second guide rail can move relative to the first guide rail along a first direction under the action of the first driving unit, and the camera can move relative to the second guide rail along a second direction under the action of the second driving unit.

[0033] Furthermore, the photographing and code reading mechanism also includes a camera adjustment plate, the camera adjustment plate is connected to the second moving component, and the camera is installed on the camera adjustment plate.

[0034] The wafer edge-finding and scanning method provided by the present application fixes the position of the reference wafer so that the center of the reference wafer coincides with the marking point in the calibration station, and the positioning part of the reference wafer faces the set direction to obtain the shooting angle of the positioning part of the reference wafer, and determine the position deviation range in the subsequent detection process, and then replace the reference wafer with the wafer to be tested, shoot the wafer mark of the wafer to be tested with the same shooting angle, and judge whether the wafer mark of the wafer to be tested is within the position deviation range, thereby improving the detection accuracy of the wafer mark of the wafer to be tested, and completing the edge patrol positioning of the wafer to be tested when adjusting the center of the wafer to be tested and the position of the positioning part. Based on this method, the method realizes the detection of the wafer mark accuracy while performing edge-finding and positioning of the wafer, thereby improving the production efficiency of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the edge-finding and code scanning device in the embodiment of the present application;

[0036] Figure 2 for Figure 1 A magnified view of point A;

[0037] Figure 3 Schematic diagram of a first shooting angle of view of the edge-finding and code scanning device in an embodiment of the present application;

[0038] Figure 4 This is a connection diagram of the processing module in the embodiment of the present application;

[0039] Figure 5 Schematic diagram of a second shooting angle of view of the edge-finding and scanning device in an embodiment of the present application;

[0040] Figure 6 for Figure 5 Enlarged view of point B;

[0041] Figure 7 This is a first flow chart of the wafer edge-finding and code scanning method in the embodiment of the present application;

[0042] Figure 8 This is the second flow chart of the wafer edge-finding and scanning method in the embodiment of the present application.

[0043] Figure numerals: 100, edge-finding and code scanning device; 10, supporting platform; 20, wafer calibrator; 21, detection unit; 22, adjustment platform; 30, moving mechanism; 31, mounting platform; 32, first moving component; 321, first guide rail; 322, first driving unit; 33, second moving component; 331, second guide rail; 332, second driving unit; 40, shooting and code reading mechanism; 41, camera; 42, code reader; 43, camera adjustment plate. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation of the present application will be clearly and completely described below in conjunction with the drawings in the implementation of the present application.

[0045] It should be noted that the directional nouns such as up, down, left, right, front, and back, or ordinal numbers such as "first" and "second" mentioned in this article are based on the drawings in the specification and are introduced for the convenience of description. They do not mean any limitation on the order of the components. In addition, since the functions of certain parts of the various components provided in the above embodiments are the same, this specification adopts a unified naming method for these parts.

[0046] like Figure 1 As shown, the present application provides a wafer edge-finding and code-scanning device 100, which includes a support platform 10, a wafer aligner 20, a moving mechanism 30, and a photographing and code-reading mechanism 40. The wafer aligner 20 is mounted on the support platform 10, and a calibration station for placing wafers is formed in the wafer aligner 20. The moving mechanism 30 is mounted on the support platform 10 and is used to drive the photographing and code-reading mechanism 40 to move. The photographing and code-reading mechanism 40 is used to photograph the wafer in the calibration station.

[0047] The wafer edge-finding and barcode scanning device 100 is equipped with a loading unit, which includes a wafer basket 200 and a robot assembly 300. The wafer basket 200 is used to store wafers, and the robot assembly 300 can grab wafers from the wafer basket 200 and transfer them to the alignment station of the wafer aligner 20. If the position and orientation of the wafer in the wafer aligner 20 need to be adjusted, this can also be achieved through the robot assembly 300.

[0048] like Figure 2 and 3 As shown, as an implementation, a wafer aligner 20 includes a detection unit 21 and an adjustment platform 22. The adjustment platform 22 is located below the alignment station and is used to support the wafer and maintain it in the alignment station. The detection unit 21 is located above the alignment station and is used to detect the center and positioning portion of the wafer. The outer edge of the wafer has a wafer flat edge (also known as a wafer flat groove, wafer groove, or wafer V-groove), which can serve as a wafer positioning portion to determine the wafer's orientation.

[0049] In the specific detection process, the detection unit 21 detects the wafer placed on the adjustment platform 22, detects the center coordinates of the wafer and the position of the positioning part, and the detection unit 21 compares the collected center coordinates of the wafer with the coordinates of the mark point 23 in the calibration station to determine the coordinate deviation. The detection unit 21 compares the direction of the collected positioning part with the set direction to determine the direction deviation, wherein the calibration station or the detection unit 21 is set with a reference direction. In the embodiment of the present application, the set direction refers to the angle of 90° formed between the positioning part and the reference direction in the horizontal direction. The detection unit 21 drives the adjustment platform 22 according to the coordinate deviation and the direction deviation, thereby adjusting the wafer by translation and rotation, so that the center coincides with the mark point 23 in the calibration station, and the positioning part faces the set direction.

[0050] For example, the detection unit 21 first captures a wafer image and uses an algorithm to determine that the coordinates of the wafer's center are (100.5, 200.3) pixels. The position of the marking point 23 in the calibration station is (100, 200) pixels, and the positioning unit deviates by 5° from the set direction. The detection unit 21 feeds this deviation data back to the adjustment platform 22. The adjustment platform 22 then translates and rotates the wafer until the wafer center is precisely moved to the (100, 200) pixel position, and simultaneously rotates the positioning unit 5° to align it with the set direction.

[0051] In some optional embodiments, the adjustment platform 22 is a circular platform that can rotate along its own circumference to adjust the direction of the wafer so that the positioning portion of the wafer is facing the set direction. When the wafer is placed in the calibration station, the center of the wafer needs to coincide with the mark point of the calibration station. The adjustment platform 22 has horizontal freedom of movement. If the center of the wafer does not coincide with the mark point of the calibration station, the adjustment platform 22 can be driven horizontally to move so that the center of the wafer coincides with the mark point of the calibration station.

[0052] In some optional embodiments, the wafer calibrator 20 is provided with a processor unit, which is electrically connected to the detection unit 21 and the adjustment platform 22 respectively. The detection unit 21 is only used to collect the center coordinates of the wafer and the position of the positioning part of the wafer, and transmit the collected data to the processor unit. The processor unit performs a specific comparison process and generates a signal representing the comparison result. The adjustment platform 22 is controlled by the signal to perform translation and rotation adjustment on the wafer so that the center coincides with the marking point in the calibration station and the positioning part faces the set direction.

[0053] The moving mechanism 30 is installed on the supporting platform 10 , and the moving mechanism 30 has at least two degrees of freedom of movement in a horizontal plane.

[0054] Exemplarily, the moving mechanism 30 is capable of moving at least along a first direction and a second direction, wherein the first direction and the second direction refer to two independent and mutually orthogonal movement directions on a horizontal plane.

[0055] The photographing and code reading mechanism 40 includes a camera 41 and a code reader 42. The camera 41 is mounted on the moving mechanism 30 and can be moved by the moving mechanism 30. The camera 41 focuses its field of view on the alignment portion of the adjusted wafer in the calibration station and captures the wafer marking located there. The code reader 42 can read the wafer marking. The wafer marking is a laser-engraved code on the wafer.

[0056] Through the above-mentioned setting, the wafer edge-finding and code-scanning device 100 can detect the wafer identification of the wafer while patrolling and positioning the wafer, thereby realizing the detection of the wafer identification accuracy and improving the production efficiency of the wafer.

[0057] In order to clearly illustrate the technical solution of the present application, the wafers are divided into reference wafers and wafers to be tested. The shooting angle position (i.e., focus position) of the camera 41 is determined by the reference wafer, and the shooting angle position of the camera 41 is kept unchanged, and then the wafer identification is detected on the wafer to be tested.

[0058] Specifically, the reference wafer is placed on the adjustment platform 22 through the robot assembly 300, and the detection unit 21 detects the reference wafer located on the adjustment platform 22 to determine the position of the center of the reference wafer and the positioning portion. The adjustment platform 22 adjusts the reference wafer based on the detection result of the detection unit 21 so that the positioning portion of the reference wafer faces the set direction. The adjustment platform 22 adjusts the reference wafer based on the detection result of the detection unit 21 so that the center of the reference wafer coincides with the mark point 23 in the calibration station. The moving mechanism 30 adjusts the camera 41 so that the shooting angle of the camera 41 is focused on the positioning portion of the reference wafer and shoots the wafer mark located at the positioning portion of the reference wafer. When the shooting angle of the camera 41 is focused on the wafer mark of the reference wafer, the shooting angle of the camera 41 remains fixed. The code reader 42 reads the wafer mark of the reference wafer.

[0059] like Figure 4 As shown, in an embodiment of the present application, the wafer edge-finding and scanning device 100 further includes a processing module 50, which is electrically connected to the camera 41. The processing module 50 is used to obtain images captured by the camera 41. These images contain position information of multiple parts on the reference wafer, wherein the multiple parts include the wafer identification of the reference wafer, the center of the reference wafer, and the positioning part of the reference wafer. The processing module 50 can set the position deviation range according to the wafer identification of the reference wafer.

[0060] Furthermore, the reference wafer is replaced with the wafer to be tested. If the center of the wafer to be tested coincides with the mark point in the calibration station and the positioning portion of the wafer to be tested faces the set direction, the wafer mark at the positioning portion of the wafer to be tested is photographed by the camera 41. It is determined whether the position of the wafer mark of the wafer to be tested is within the position deviation range. If the position of the wafer mark of the wafer to be tested is within the position deviation range, the accuracy of the wafer mark of the wafer to be tested is tested; if the position of the wafer mark of the wafer to be tested is outside the position deviation range, the wafer to be tested is calibrated as a defective wafer.

[0061] Through the above-mentioned setting, the position and accuracy of the wafer mark of the wafer to be tested can be effectively detected, which helps to ensure the accuracy and consistency of the subsequent detection process.

[0062] As an implementation method, the detection unit 21 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 angular difference between the reference direction and the set direction. The processing module 50 is configured to generate wafer edge data based on the sampling results of the detection unit 21. The processing module 50 is further configured to locate the wafer identifier, center of the circle, and the position of the positioning portion of the wafer to obtain positioning data, fit the edge data to the positioning data, and compare the fitting result with the set standard data to determine the accuracy of the wafer identifier.

[0063] Through the above settings, the edge-finding and code scanning device 100 integrates the functions of wafer edge-finding and wafer marking processing accuracy detection, thereby improving the detection efficiency of wafer quality and reducing detection costs.

[0064] Furthermore, the processing module 50 is further configured to adjust the grayscale value of the image so that the difference between the grayscale value of the wafer mark on the wafer and the grayscale value of the image background is greater than a set grayscale value threshold.

[0065] Exemplarily, the grayscale value of the wafer mark of the wafer to be tested is adjusted to 100, and the grayscale value of the background is adjusted to 50.

[0066] Through the above settings, the contrast of the wafer mark in the image is improved, and the subsequent code reading process can more accurately identify and locate the wafer mark of the wafer, thereby improving the detection accuracy of the wafer mark of the wafer.

[0067] like Figure 5 and Figure 6As shown, as an implementation, the mobile mechanism 30 includes a mounting platform 31, a first mobile assembly 32, and a second mobile assembly 33. The mounting platform 31 is fixed to the support platform 10 and serves as a support for the mobile mechanism 30, ensuring the stability of the subsequent components. The first mobile assembly 32 is mounted on the mounting platform 31 and is capable of driving the second mobile assembly 33 to move in a first direction. The camera 41 is mounted on the second mobile assembly 33, and the second mobile assembly 33 is mounted on the first mobile assembly 32. The second mobile assembly 33 is capable of driving the camera 41 to move in a second direction.

[0068] Furthermore, the first moving component 32 includes a first guide rail 321 and a first driving unit 322, and the second moving component 33 includes a second guide rail 331 and a second driving unit 332. The first guide rail 321 is fixed to the mounting platform 31, and the second guide rail 331 can move relative to the first guide rail 321 along the first direction under the action of the first driving unit 322. The camera 41 can move relative to the second guide rail 331 along the second direction under the action of the second driving unit 332.

[0069] Specifically, the first drive unit 322 drives the second guide rail 331 to move relative to the first guide rail 321 in a first direction, thereby achieving continuous and controllable movement of the second guide rail 331 in the first direction, thereby ensuring the positioning accuracy of the camera 41 in the first direction. The second drive unit 332 drives the camera 41 to move relative to the second guide rail 331 in a second direction, thereby achieving precise movement of the camera 41 in the second direction. This allows the camera 41 to have at least two degrees of freedom of movement in the horizontal plane, allowing it to reach any predetermined position in the horizontal plane, thereby ensuring that the target area (such as the wafer mark of the reference wafer) is always within the field of view of the camera 41.

[0070] Through the above arrangement, the mobile mechanism 30 has high-precision, multi-degree-of-freedom positioning capabilities, providing a stable and reliable mobile platform for the camera 41, ensuring that the camera 41 can always accurately focus on the target area during scanning or edge finding.

[0071] like Figure 3 As shown, further, the shooting and code reading mechanism 40 also includes a camera adjustment plate 43, the camera adjustment plate 43 is connected to the second moving component 33, the camera 41 is installed on the camera adjustment plate 43, the camera adjustment plate 43 serves to connect and fix the camera 41, and the camera adjustment plate 43 is also used to adjust the distance between the camera 41 and the wafer.

[0072] like Figure 7 As shown, the present application also provides a wafer edge finding and scanning method, which includes the following steps:

[0073] Step S601: When the reference wafer is placed on the calibration station, the center of the reference wafer and the position of the positioning portion are adjusted.

[0074] Exemplarily, the reference wafer is placed on the adjustment platform 22, and based on the detection unit 21, the center of the reference wafer and the positioning part are detected. The adjustment platform 22 can adjust the reference wafer in the calibration station according to the detection results of the detection unit 21, so that the center of the reference wafer coincides with the marking point in the calibration station, and the positioning part of the reference wafer is oriented in the set direction, wherein the outer edge of the reference wafer has a wafer flat edge (also known as a wafer flat groove, wafer groove, wafer V-groove), and the wafer flat edge can be used as the positioning part of the reference wafer to determine the direction of the reference wafer.

[0075] In some embodiments, since the wafer loading position is different, the set direction can be flexibly adjusted according to the wafer loading position.

[0076] Step S602 : focusing the shooting angle of view on the positioning portion of the reference wafer and fixing the shooting angle of view.

[0077] The position of the camera 41 is adjusted by the moving mechanism 30 so that the shooting angle of the camera 41 is focused on the positioning portion of the reference wafer. When the shooting angle of the camera 41 is focused on the positioning portion of the reference wafer, the camera 41 is stopped from moving, thereby fixing the shooting angle of the camera 41.

[0078] It should be noted that, during the subsequent inspection process of the wafer to be inspected, the shooting angle of the camera 41 remains unchanged.

[0079] Step S603 : photographing the wafer mark located at the positioning portion of the reference wafer, and setting a position deviation range based on the position of the wafer mark of the reference wafer.

[0080] Step S604: Replace the reference wafer with the wafer to be tested, adjust the center of the wafer to be tested to coincide with the marking point in the calibration station, and adjust the positioning portion of the wafer to be tested to face the set direction.

[0081] Step S605 : photographing the wafer mark at the positioning portion of the wafer to be tested. If the position of the wafer mark of the wafer to be tested is within the position deviation range, the accuracy of the wafer mark of the wafer to be tested is tested.

[0082] Exemplarily, with the position of the wafer mark of the reference wafer as a reference, a position deviation range of ±1 mm is set, that is, the deviation in the horizontal direction between the position of the wafer mark of the wafer to be measured and the position of the wafer mark of the reference wafer cannot exceed 1 mm.

[0083] In an embodiment of the present application, if the position of the wafer mark of the wafer to be tested is outside the position deviation range, the wafer to be tested is determined to be a defective wafer.

[0084] like Figure 8 As shown, in some embodiments, step S605: detecting the accuracy of wafer marking of the wafer to be tested includes:

[0085] Step S6051: Based on the captured image, the center of the wafer to be measured, the positioning portion, and the position of the wafer mark are located to obtain positioning data.

[0086] For example, the processing unit 50 can calculate the relative position between the center of the wafer to be tested and the positioning portion based on the positioning portion of the wafer to be tested and the size of the wafer to be tested, and adjust the wafer to be tested based on the relative position between the center of the wafer to be tested and the positioning portion so that the center of the wafer to be tested coincides with the marked point. In addition, the processing unit 50 calculates the center position of the wafer to be tested, combines it with the position of the positioning portion and the wafer mark, and obtains the positioning data of the wafer to be tested.

[0087] Step S6052: sampling the size, edge position and relative angle of the wafer to be measured to obtain edge data.

[0088] The calibration station is set with a reference direction, and the relative angle is the angle difference between the reference direction and the set direction.

[0089] Step S6053: 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 to be tested.

[0090] Exemplarily, the processing unit 50 can draw a fitting curve representing the wafer to be tested based on the edge data and positioning data; compare the fitting curve with the standard data to obtain the fitting degree of the wafer to be tested; if the fitting degree is outside the preset threshold range, the wafer to be tested is determined to be a defective wafer.

[0091] In summary, by fixing the position of the reference wafer, making the center of the reference wafer coincide with the marking point in the calibration station, and the positioning part of the reference wafer facing the set direction, the shooting angle of the positioning part of the reference wafer is obtained, and the position deviation range in the subsequent detection process is determined, and then the reference wafer is replaced with the wafer to be tested, and the wafer mark of the wafer to be tested is photographed with the same shooting angle, and it is determined whether the wafer mark of the wafer to be tested is within the position deviation range, thereby improving the detection accuracy of the wafer mark of the wafer to be tested, and completing the edge positioning of the wafer to be tested when adjusting the center of the circle and the position of the positioning part of the wafer to be tested. Based on this method, the method realizes the detection of the wafer mark accuracy while performing edge positioning on the wafer, thereby improving the production efficiency of the wafer.

[0092] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims appended to this application.

Claims

1. A wafer edge scanning method, characterized in that: The method comprises: When the reference wafer is placed in the calibration station, the center of the reference wafer and the position of the positioning portion are adjusted so that the center of the reference wafer coincides with the mark point in the calibration station and the positioning portion of the reference wafer faces the set direction; Focusing a shooting angle of view on the positioning portion of the reference wafer and fixing the shooting angle of view; photographing a wafer mark located at a positioning portion of the reference wafer, and setting a position deviation range based on a position of the wafer mark of the reference wafer; Replacing the reference wafer with the wafer to be tested, adjusting the center of the wafer to be tested to coincide with the marking point in the calibration station, and with the positioning portion of the wafer to be tested facing the set direction; photographing a wafer mark at a positioning portion of the wafer to be tested, and if the position of the wafer mark of the wafer to be tested is within the position deviation range, locating the center of the wafer to be tested, the positioning portion, and the position of the wafer mark based on the photographed image to obtain positioning data; Sampling the size, edge position and relative angle of the wafer to be measured to obtain edge data, wherein the calibration station is set with a reference direction, and the relative angle is the angle difference between the reference direction and the set direction; The edge data is fitted with the positioning data, and the fitting result is compared with the preset standard data to determine the accuracy of the wafer to be measured.

2. The wafer edge-finding and code scanning method according to claim 1, characterized in that: The method further comprises: If the position of the wafer mark of the wafer to be tested is outside the position deviation range, it is determined that the wafer to be tested is a defective wafer.

3. The wafer edge-finding and code scanning method according to claim 1, characterized in that: Before locating the center of the wafer to be tested, the positioning portion, and the wafer mark based on the captured image, the method includes: The grayscale value of the captured image is adjusted so that the difference between the grayscale value of the wafer mark of the wafer to be tested and the grayscale value of the image background is greater than a set grayscale value threshold.

4. The wafer edge-finding and code scanning method according to claim 1, wherein: The step of fitting the edge data with the positioning data and comparing the fitting result with preset standard data to determine the accuracy of the wafer to be measured includes: Drawing a fitting curve representing the wafer to be tested based on the edge data and the positioning data; Comparing the fitting curve with the standard data to obtain the fitting degree of the wafer to be tested; If the degree of fit is outside a preset threshold range, the wafer to be tested is determined to be a defective wafer.

5. A wafer edge-finding and code scanning device, characterized in that: include: Support platform (10); A wafer calibrator (20), the wafer calibrator (20) being mounted on the supporting platform (10), forming a calibration station for placing wafers in the wafer calibrator (20), the wafer calibrator (20) comprising a detection unit (21) and an adjustment platform (22), the adjustment platform (22) being used to support the wafer so that the wafer remains in the calibration station, the detection unit (21) being used to detect the center of the wafer and the position of the positioning portion, and driving the adjustment platform (22) according to the detection result so that the center of the wafer coincides with a marking point in the calibration station and the positioning portion faces a set direction; A moving mechanism (30), the moving mechanism (30) being mounted on the supporting platform (10), the moving mechanism (30) having at least two degrees of freedom of movement in a horizontal plane; A photographing and code reading mechanism (40), the photographing and code reading mechanism (40) comprising a camera (41) and a code reader (42), the camera (41) being mounted on the moving mechanism (30) and being capable of moving under the drive of the moving mechanism (30), so that the photographing angle of the camera (41) is focused on the positioning portion, the camera (41) being used to photograph a wafer mark located at the positioning portion, and the code reader (42) being capable of reading the wafer mark; A processing module (50), wherein the processing module (50) is electrically connected to the detection unit (21), and the detection unit (21) is further used to sample the size, edge position and relative angle of the wafer, wherein the calibration station is set with a reference direction, and the relative angle is the angle difference between the reference direction and the set direction. The processing module (50) can generate edge data of the wafer according to the sampling result of the detection unit (21); the processing module (50) can also locate the wafer mark, the center of the circle and the position of the positioning part of the wafer based on the image taken by the camera (41) to obtain positioning data, and fit the edge data with the positioning data, compare the fitting result with the preset standard data, and determine the accuracy of the wafer mark.

6. The wafer edge-finding and code scanning device according to claim 5, characterized in that: The moving mechanism (30) comprises a mounting platform (31), a first moving component (32) and a second moving component (33), wherein the mounting platform (31) is fixed to the supporting platform (10), the first moving component (32) is mounted on the mounting platform (31) and is capable of driving the second moving component (33) to move along a first direction, and the second moving component (33) is mounted on the first moving component (32) and is capable of driving the camera (41) to move along a second direction, wherein the first direction is different from the second direction.

7. The wafer edge-finding and code scanning device according to claim 6, characterized in that: The first moving assembly (32) includes a first guide rail (321) and a first driving unit (322); the second moving assembly (33) includes a second guide rail (331) and a second driving unit (332); the first guide rail (321) is fixed to the mounting platform (31); the second guide rail (331) can be moved relative to the first guide rail (321) along the first direction under the action of the first driving unit (322); and the camera (41) can be moved relative to the second guide rail (331) along the second direction under the action of the second driving unit (332).

8. The wafer edge-finding and code scanning device according to claim 6, wherein: The photographing and code reading mechanism (40) further includes a camera adjustment plate (43), the camera adjustment plate (43) is connected to the second moving assembly (33), and the camera (41) is mounted on the camera adjustment plate (43).

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