Wafer Calibration Method, Device, Equipment and Medium Based on Machine Vision

Abstract

The present invention discloses a wafer calibration method, device, equipment and medium based on machine vision. The method includes: determining the center position of the tray rotation according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray; placing the target wafer within the reference circle scale line on the tray, and collecting an image of the tray to obtain a target image; based on the target image, determining the center position of the wafer according to the distance between the reference circle scale line and the target wafer; based on the target image, determining the wafer offset angle according to the reference circle scale line, the center position of the wafer and the wafer notch identification information; and performing position calibration on the test points on the target wafer according to the center position of the tray rotation, the center position of the wafer and the wafer offset angle. The present invention improves the wafer calibration efficiency and avoids the need to repeatedly take the wafer back and forth from the wafer carrier to the wafer calibrator and then to the process position during wafer calibration.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer calibration, and particularly relates to a wafer calibration method, device, equipment and medium based on machine vision. Background Art

[0002] The four-probe resistance measuring instrument is applied in the semiconductor process field to measure the sheet resistance or resistivity of thin films such as implantation, diffusion, epitaxy, and metal coating. The full-automatic four-probe resistance measuring instrument generally consists of a wafer carrier, a manipulator, a wafer calibrator, and a measuring part. Since there is a certain gap when placing the wafer in the wafer carrier, the wafer edge defect (or notch) is also random, and the operation on the wafer at the process position needs to be accurate to the specific position. In order to ensure the accuracy of the operation on the wafer at the process position, it is necessary to calibrate the center point of the wafer with the edge defect (or notch).

[0003] The existing technology uses the wafer calibrator in the full-automatic four-probe resistance measuring instrument to calibrate the position of the wafer. The wafer calibrator is a device for positioning the center of the wafer and the edge defect (or notch) of the wafer. The manipulator in the full-automatic four-probe resistance measuring instrument places the wafer on the wafer calibrator. The wafer calibrator rotates, and by identifying the position of the edge defect (or notch) of the wafer, the deviation of the center point and the orientation of the edge defect (or notch) of the wafer are adjusted. The manipulator takes out the wafer from the wafer calibrator again and places it on the process position. After the wafer finishes working at the process position, the manipulator takes the wafer from the process position again and puts it back into the wafer carrier. Then, when continuing to work, it is necessary to take the wafer from the wafer carrier again and place it on the wafer calibrator for calibration, and then put it on the process position. The operation from calibration to work is smooth and complex, affecting the wafer utilization efficiency. Therefore, an efficient calibration method for the wafer is needed. Summary of the Invention

[0004] The present invention provides a wafer calibration method, device, equipment and medium based on machine vision to improve the wafer calibration efficiency and avoid the need to repeatedly take the wafer back and forth from the wafer carrier to the wafer calibrator and then to the process position when calibrating the wafer.

[0005] According to one aspect of the present invention, a wafer calibration method based on machine vision is provided, including:

[0006] Determining the position of the rotation center of the tray according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray;

[0007] Placing the target wafer within the reference circle scale line on the tray and collecting an image of the tray to obtain a target image;

[0008] Based on the target image, determining the position of the center of the wafer according to the distance between the reference circle scale line and the target wafer;

[0009] Based on the target image, determine the wafer offset angle according to the reference circle scale line, the position of the wafer center, and the wafer notch identification information;

[0010] Perform position calibration on the test points on the target wafer according to the position of the tray rotation center, the position of the wafer center, and the wafer offset angle.

[0011] According to another aspect of the present invention, there is provided a wafer calibration device based on machine vision, including:

[0012] A rotation center determination module, configured to determine the position of the tray rotation center according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray;

[0013] A wafer image acquisition module, configured to place the target wafer within the reference circle scale line on the tray, and perform image acquisition on the tray to obtain a target image;

[0014] A wafer center position determination module, configured to determine the position of the wafer center based on the target image according to the distance between the reference circle scale line and the target wafer;

[0015] A wafer offset angle determination module, configured to determine the wafer offset angle based on the target image according to the reference circle scale line, the position of the wafer center, and the wafer notch identification information;

[0016] A position calibration module, configured to perform position calibration on the test points on the target wafer according to the position of the tray rotation center, the position of the wafer center, and the wafer offset angle.

[0017] According to another aspect of the present invention, there is provided an electronic device, the electronic device includes:

[0018] At least one processor; and

[0019] A memory communicatively connected to the at least one processor; wherein,

[0020] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the machine vision-based wafer calibration method according to any embodiment of the present invention.

[0021] According to another aspect of the present invention, there is provided a computer-readable storage medium, the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a processor to implement the machine vision-based wafer calibration method according to any embodiment of the present invention when executed.

[0022] In the embodiment of the present invention, the calibration of the wafer is realized through simple machine vision operations, which improves the calibration accuracy of the wafer, reduces the efficiency of wafer calibration, avoids repeatedly picking up the wafer from the process position to the calibrator during wafer calibration, and reduces the calibration operation process; calibrating the wafer directly at the process position also reduces the space required for wafer calibration.

[0023] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 is a flowchart of a wafer calibration method based on machine vision according to Embodiment 1 of the present invention;

[0026] Figure 2 is a flowchart of another wafer calibration method based on machine vision according to Embodiment 1 of the present invention;

[0027] Figure 3 is a schematic diagram of a reference circle scale line and a vertical positioning point;

[0028] Figure 4 is a schematic structural diagram of a wafer calibration device based on machine vision according to Embodiment 3 of the present invention;

[0029] Figure 5 is a schematic structural diagram of an electronic device for implementing the wafer calibration method based on machine vision in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention shall fall within the protection scope of the present invention.

[0031] It should be noted that the terms "candidate", "target", etc. in the specification, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0032] Embodiment 1

[0033] Figure 1 FIG. 1 is a flowchart of a wafer calibration method based on machine vision provided for Embodiment 1 of the present invention. This embodiment is applicable to the case of calibrating the center position and notch angle of a wafer. This method can be executed by a wafer calibration device based on machine vision. The wafer calibration device based on machine vision can be implemented in the form of hardware and / or software, and the wafer calibration device based on machine vision can be configured in a device with computing capabilities. As Figure 1 shown, the method includes:

[0034] S110. Determine the tray rotation center position according to the tray image obtained by the rotation of the motor.

[0035] Among them, a reference circle scale line with a radius larger than the radius of the target wafer is engraved on the tray.

[0036] The tray refers to the platform for placing the wafer on the wafer process position, and operations on the wafer are performed at the process position. The motor refers to the control device for rotating the tray. The motor rotates to drive the tray to rotate to adjust the position of the wafer placed on the tray.

[0037] Since the motor drives the tray to rotate, and the tray is fixed on the motor rotation shaft through structural parts, due to the influence of installation gaps and installation errors, etc., the tray center and the tray rotation center are not in the same position, there is an error. Therefore, in order to ensure the accuracy of subsequent calibration, it is necessary to calibrate the deviation between the tray center and the tray rotation center.

[0038] Specifically, determine the tray rotation center position according to the position change information of the tray center when the motor rotates. Among them, the tray center can be determined by a fixed reference center point mark on the tray, or determined by the result of circular fitting of the tray.

[0039] Meanwhile, a reference circle scale line is engraved on the tray. The reference circle scale line takes the center of the tray as the origin. The radius of the circle of the reference circle scale line is greater than the wafer radius of the target wafer, and the difference between the radius of the circle of the reference circle scale line and the wafer radius of the target wafer is greater than the first gap and less than the second gap. The specific values of the first gap and the second gap can be determined according to the actual size of the tray and the size of the target wafer, and are not limited herein. Exemplarily, the difference between the radius of the circle of the reference circle scale line and the wafer radius of the target wafer is 5 mm.

[0040] In a feasible embodiment, S110 includes:

[0041] Collect the first tray image corresponding to the motor rotating the first angle, perform tray position fitting according to the first tray image, and determine the first tray center position according to the fitting result;

[0042] Collect the second tray image corresponding to the motor rotating the second angle, perform tray position fitting according to the second tray image, and determine the second tray center position according to the fitting result; wherein, the difference between the second angle and the first angle is a preset angle;

[0043] Determine the tray rotation center position according to the first tray center position, the second tray center position, and the preset angle.

[0044] Specifically, an image acquisition device, such as a camera, is installed above the process position to acquire images of the tray and the target wafer on the tray for visual calibration according to the acquired images. The installation of the image acquisition device requires that the center of the image acquisition device, the center of the light source, and the center of the tray are on the same line, and the plane of the image acquisition device, the plane of the light source, and the plane of the tray are horizontal. Among them, the light source is used for supplementary lighting during image acquisition to ensure the clarity of the image.

[0045] When the motor rotates the first angle, an image of the tray is acquired once to obtain the first tray image. The tray in the first tray image is subjected to circle fitting, and the center position of the circle fitting result is the first tray center position; similarly, when the motor rotates the second angle, an image of the tray is acquired once to obtain the second tray image. The tray in the second tray image is subjected to circle fitting, and the center position of the circle fitting result is the second tray center position. If the tray center is consistent with the tray rotation center, the first tray center position and the second tray center position are the same. If they are different, it means that there is an error between the tray center and the tray rotation center. The tray rotation center position is determined according to the positional relationship between the rotation angle and the change in the tray center position. For example, the preset angle is 90 degrees.

[0046] Exemplarily, when the rotating motor rotates 0 degrees, an image of the tray is collected once to obtain the first tray image. The tray in the first tray image is subjected to circle fitting, and the center position of the circle fitting result is the first tray center position p1 (p1.x, p1.y). Similarly, when the rotating motor rotates 180 degrees, an image of the tray is collected once to obtain the second tray image. The tray in the second tray image is subjected to circle fitting, and the center position of the circle fitting result is the second tray center position p2 (p2.x, p2.y). Then the tray rotation center position p ((p1.x + p2.x) / 2, (p1.y + p2.y) / 2). Similarly, at other preset angles, it can be deduced according to the position relationship, which is not limited here. Optionally, multiple groups of preset angles can be used to obtain multiple tray rotation center positions to ensure the accuracy of determining the tray rotation center position.

[0047] S120. Place the target wafer within the reference circle scale line on the tray, and collect an image of the tray to obtain the target image.

[0048] Control the manipulator to operate to place the target wafer within the reference circle scale line. For example, determine the position movement information of the manipulator according to the position information of the manipulator, the position information of the tray, and the position information of the reference circle scale line, so as to place the target wafer according to the position movement information, and the target wafer can be controlled to be placed within the reference circle scale line on the tray. Or control the placement of the target wafer within the reference circle scale line on the tray through the image recognition result collected by the image acquisition device. After the target wafer is placed, take a picture of the tray to obtain the target image.

[0049] S130. Based on the target image, determine the wafer center position according to the distance between the reference circle scale line and the target wafer.

[0050] Since both the reference circle scale line and the target wafer are circular, the center position of the target wafer can be determined according to the position relationship between the reference circle scale line and the target wafer. For example, through the image recognition information of the target image, determine the position of the point passing through the center according to the distance between the reference circle scale line and the target wafer, and then determine the wafer center position according to the position of the point passing through the center.

[0051] S140. Based on the target image, determine the wafer offset angle according to the reference circle scale line, the wafer center position, and the wafer notch recognition information.

[0052] The wafer offset angle refers to the angle information of the notch on the wafer deviating from the horizontal or the vertical direction. Specifically, determine the horizontal or the vertical direction according to the wafer center position and the reference circle scale line, and then determine the included angle between the notch and the horizontal or the vertical direction in the target image as the wafer offset angle according to the wafer notch recognition information.

[0053] S150. Calibrate the positions of the test points on the target wafer according to the position of the tray rotation center, the position of the wafer center, and the wafer offset angle.

[0054] The test points on the target wafer refer to multiple fixed points pre-marked on the target wafer.

[0055] Specifically, determine the center point offset according to the tray rotation center position and the wafer center position, and then calibrate the initial test point positions according to the center point offset and the wafer offset angle, and calculate the positions of the rotation motor and the linear motion motor according to the calibrated test point positions. Exemplarily, the test sequence is included among the multiple test points, and the position calculations are performed in sequence according to the test sequence.

[0056] Among them, calibrate the positions of the test points on the target wafer according to the tray rotation center position, the wafer center position, and the wafer offset angle based on the following formula, including:

[0057] x2 = (x1 + dx) * cos(θ) + (y1 + dy) * sin(θ)

[0058] y2 = -(x1 + dx) * sin(θ) + (y1 + dy) * cos(θ);

[0059] Among them, (x1, y1) is the initial test point position of the test point on the target wafer, (x1, y1) is the calibrated test point position, (dx, dy) is the center point offset, and θ is the wafer offset angle.

[0060] The embodiment of the present invention realizes the calibration of the wafer through simple machine vision operations, improves the calibration accuracy of the wafer, and reduces the efficiency of wafer calibration. It avoids the need to repeatedly pick up the wafer from the process position to the calibrator during wafer calibration, reducing the calibration operation process; calibrating the wafer directly at the process position also reduces the space required for wafer calibration.

[0061] Embodiment Two

[0062] Figure 2 The flowchart of a wafer calibration method based on machine vision provided by the second embodiment of the present invention further details the technical solutions in the above embodiments. As Figure 2 shown, the method includes:

[0063] S210. Determine the tray rotation center position according to the tray image obtained by the motor rotation.

[0064] Among them, a reference circle scale line with a radius larger than the radius of the target wafer is engraved on the tray, and two vertical positioning points are included on the reference circle scale line, and the connection line of the two vertical positioning points passes through the tray center.

[0065] The line connecting the vertical positioning points is the vertical diameter on the reference circle scale line, which is used for reference positioning of the wafer placement position to improve the efficiency of determining the wafer offset angle. As Figure 3 The schematic diagram of the reference circle scale line and the vertical positioning points is shown. Points A and C are the vertical positioning points.

[0066] S220. Based on the notch of the target wafer and taking the target vertical positioning point as the reference point, place the target wafer on the tray and perform image acquisition on the tray to obtain the target image.

[0067] Among them, the target vertical positioning point is the lower vertical positioning point among the two vertical positioning points.

[0068] As Figure 3 shown, point C is the target vertical positioning point. In order to facilitate the subsequent determination of the wafer offset angle, align the notch of the target wafer with the target vertical positioning point to place the target wafer. Due to deviation, the notch position of the target wafer is close to but does not coincide with the target vertical positioning point.

[0069] S230. According to the recognition result of the target image, determine the maximum distance and the minimum distance between the reference circle scale line and the target wafer; according to the connection line between the reference circle scale line corresponding to the maximum distance and the target wafer, determine the maximum distance point on the target wafer; according to the connection line between the reference circle scale line corresponding to the minimum distance and the target wafer, determine the minimum distance point on the target wafer; determine the wafer center position according to the maximum distance point and the minimum distance point.

[0070] The target wafer is located within the reference circle scale line. Sequentially determine the distances between each point on the reference circle scale line and the target wafer to determine the maximum distance and the minimum distance. The point on the target wafer corresponding to the maximum distance is the maximum distance point, and the point on the target wafer corresponding to the minimum distance is the minimum distance point. As Figure 3 shown, point E is the maximum distance point and point F is the minimum distance point. According to the characteristics of the circle, the connection line between the maximum distance point and the minimum distance point passes through the center of the circle, that is, the connection line between the maximum distance point and the minimum distance point is the diameter of the target wafer. Determine the wafer center position according to the position information of the maximum distance point and the minimum distance point and taking half of the value.

[0071] In a feasible embodiment, determining the maximum distance and the minimum distance between the reference circle scale line and the target wafer includes:

[0072] Traverse each point on the reference circle scale line as the target reference point;

[0073] Determine the shortest distance between the target reference point and the target wafer, and take the shortest distance as the target distance between the target reference point and the target wafer;

[0074] Determine the maximum distance and the minimum distance from the target distance between the target reference point and the target wafer.

[0075] Determine the distances between each point on the reference circle scale line and the target wafer respectively. When determining a certain point, this point serves as the target reference point. The shortest distance between the target reference point and each point on the target wafer is the target distance between this target reference point and the target wafer. Obtain the target distances between each point on the reference circle scale line and the target wafer, and sort them according to the target distances to obtain the maximum distance and the minimum distance.

[0076] In a feasible embodiment, before determining the position of the wafer center according to the maximum distance point and the minimum distance point, the method further includes:

[0077] Determine whether the maximum distance point is located at the wafer notch position;

[0078] If it is located, re-determine the maximum distance point;

[0079] Correspondingly, after determining the position of the wafer center according to the maximum distance point and the minimum distance point, the method further includes:

[0080] Determine the position offset between the wafer center position and the tray rotation center position;

[0081] If the position offset is greater than the preset offset threshold, re-execute the operation of placing the target wafer within the reference circle scale line on the tray to re-calibrate the target wafer.

[0082] Specifically, after determining the maximum distance point on the target wafer, judge whether the maximum distance point is located at the wafer notch position. If it is located at the wafer notch position, it will cause inaccurate identification of the wafer center position. Therefore, judge the maximum distance point. If it is located, re-determine the maximum distance point.

[0083] Similarly, in order to avoid the problem of identification error in judging according to the wafer notch position, and to avoid the maximum distance point just falling on the wafer notch position when placing the wafer, after determining the position of the wafer center according to the maximum distance point and the minimum distance point, determine the position offset between the wafer center position and the tray rotation center position. If the position offset is large, it proves that the determination of the wafer center position is incorrect, that is, the positioning of the maximum distance point and the minimum distance point is inaccurate. Then re-place the target wafer and re-execute the calibration process to improve the accuracy of determining the wafer center position.

[0084] S240. Determine the wafer notch position according to the wafer notch recognition information of the target image; determine the target positioning line according to the positions of two vertical positioning points on the reference circle scale line; determine the offset line according to the wafer center position and the wafer notch position; determine the angle between the target positioning line and the offset line as the wafer offset angle.

[0085] Perform image recognition on the target image based on the wafer notch feature to obtain the wafer notch position. If the wafer notch is a region, use the center point of the recognized notch region as the wafer notch position. Connect the positions of two vertical positioning points on the reference circle scale line as the target positioning line, and connect the positions of the wafer center and the wafer notch position as the offset line. Determine the angle between the target positioning line and the offset line as the wafer offset angle. Similarly, as Figure 3 shown, the reference circle scale line may also include a horizontal positioning point B to determine the horizontal target positioning line based on the horizontal positioning point and determine the wafer offset angle.

[0086] S250. Determine the initial test point position of the test points on the target wafer; determine the center point offset according to the tray rotation center position and the wafer center position; perform position calibration on the initial test point position according to the center point offset and the wafer offset angle to obtain the calibrated test point position.

[0087] Establish a unified coordinate system according to the image acquisition device. All positions in the embodiments of the present invention are in the same coordinate system to ensure the accuracy of position information determination and improve the calculation efficiency. Determine the test points on the target wafer and determine the initial test point positions of each test point in the camera coordinate system. Determine the center point offset according to the tray rotation center position and the wafer center position, and then perform position calibration on the initial test point position according to the center point offset and the wafer offset angle to obtain the calibrated test point position. To perform motion control of the motor shaft according to the calibrated test point position.

[0088] Among them, perform position calibration on the initial test point position according to the center point offset and the wafer offset angle based on the following formula, including:

[0089] x2 = (x1 + dx) * cos(θ) + (y1 + dy) * sin(θ)

[0090] y2 = -(x1 + dx) * sin(θ) + (y1 + dy) * cos(θ);

[0091] Among them, (x1, y1) is the initial test point position, (x1, y1) is the calibrated test point position, (dx, dy) is the center point offset, and θ is the wafer offset angle.

[0092] The technical solution of the embodiment of the present invention can effectively detect calibration errors during the calibration process and improve the calibration accuracy by judging the wafer center position and calibrating and judging from other machine vision angles.

[0093] Embodiment III

[0094] Figure 4This is a schematic structural diagram of a wafer calibration device based on machine vision provided in Embodiment 3 of the present invention. As Figure 4 shown, the device includes:

[0095] A rotation center determination module 410, configured to determine the position of the tray rotation center according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray;

[0096] A wafer image acquisition module 420, configured to place the target wafer within the reference circle scale line on the tray and perform image acquisition on the tray to obtain a target image;

[0097] A wafer center position determination module 430, configured to determine the wafer center position based on the target image according to the distance between the reference circle scale line and the target wafer;

[0098] A wafer offset angle determination module 440, configured to determine the wafer offset angle based on the target image according to the reference circle scale line, the wafer center position, and the wafer notch identification information;

[0099] A position calibration module 450, configured to perform position calibration on the test points on the target wafer according to the tray rotation center position, the wafer center position, and the wafer offset angle.

[0100] Through simple machine vision operations in the embodiments of the present invention, the calibration of the wafer is realized, the calibration accuracy of the wafer is improved, and the efficiency of wafer calibration is reduced. It is avoided that the wafer needs to be repeatedly taken from the process position to the calibrator for calibration, and the calibration operation process is reduced; directly calibrating the wafer at the process position also reduces the space required for wafer calibration.

[0101] Optionally, the wafer center position determination module includes:

[0102] A distance determination unit, configured to determine the maximum distance and the minimum distance between the reference circle scale line and the target wafer according to the recognition result of the target image;

[0103] A first distance point determination unit, configured to determine the maximum distance point on the target wafer according to the connection line between the reference circle scale line corresponding to the maximum distance and the target wafer;

[0104] A second distance point determination unit, configured to determine the minimum distance point on the target wafer according to the connection line between the reference circle scale line corresponding to the minimum distance and the target wafer;

[0105] A center position determination unit, configured to determine the wafer center position according to the maximum distance point and the minimum distance point.

[0106] Optionally, the distance determination unit is specifically configured to:

[0107] Traverse each point on the reference circle scale line as the target reference point;

[0108] Determine the shortest distance between the target reference point and the target wafer, and use the shortest distance as the target distance between the target reference point and the target wafer;

[0109] Determine the maximum distance and the minimum distance from the target distances between the target reference point and the target wafer.

[0110] Optionally, the crystal wafer center position determination module further includes a distance point judgment unit, configured to:

[0111] Before determining the crystal wafer center position according to the maximum distance point and the minimum distance point,

[0112] Determine whether the maximum distance point is located at the wafer notch position;

[0113] If it is located, re-determine the maximum distance point;

[0114] Correspondingly, the device further includes a position offset judgment module, configured to:

[0115] After determining the crystal wafer center position according to the maximum distance point and the minimum distance point,

[0116] Determine the position offset between the crystal wafer center position and the tray rotation center position;

[0117] If the position offset is greater than a preset offset threshold, re-execute the operation of placing the target wafer within the reference circle scale line on the tray to re-calibrate the target wafer.

[0118] Optionally, the reference circle scale line includes two vertical positioning points, and the line connecting the two vertical positioning points passes through the tray center;

[0119] Correspondingly, the wafer image acquisition module is specifically configured to:

[0120] Based on the notch of the target wafer with the target vertical positioning point as the reference point, place the target wafer on the tray; wherein, the target vertical positioning point is the lower vertical positioning point among the two vertical positioning points;

[0121] Correspondingly, the wafer offset angle determination module is specifically configured to:

[0122] Determine the wafer notch position according to the wafer notch recognition information of the target image;

[0123] Determine the target positioning line according to the positions of two perpendicular positioning points on the reference circle scale line;

[0124] Determine the offset line according to the position of the wafer center and the position of the wafer notch;

[0125] Determine the angle between the target positioning line and the offset line as the wafer offset angle.

[0126] Optionally, the position calibration module is specifically configured to:

[0127] Determine the initial test point position of the test point on the target wafer;

[0128] Determine the center point offset according to the position of the tray rotation center and the position of the wafer center;

[0129] Perform position calibration on the initial test point position according to the center point offset and the wafer offset angle to obtain the calibrated test point position;

[0130] Among them, performing position calibration on the initial test point position according to the center point offset and the wafer offset angle based on the following formula includes:

[0131] x2 = (x1 + dx) * cos(θ) + (y1 + dy) * sin(θ)

[0132] y2 = -(x1 + dx) * sin(θ) + (y1 + dy) * cos(θ);

[0133] Among them, (x1, y1) is the initial test point position, (x1, y1) is the calibrated test point position, (dx, dy) is the center point offset, and θ is the wafer offset angle.

[0134] Optionally, the rotation center determination module is specifically configured to:

[0135] Collect the first tray image corresponding to the first rotation angle of the motor, perform tray position fitting according to the first tray image, and determine the first tray center position according to the fitting result;

[0136] Collect the second tray image corresponding to the second rotation angle of the motor, perform tray position fitting according to the second tray image, and determine the second tray center position according to the fitting result; wherein, the difference between the second angle and the first angle is a preset angle;

[0137] Determine the tray rotation center position according to the first tray center position, the second tray center position, and the preset angle.

[0138] The wafer calibration device based on machine vision provided by the embodiments of the present invention can execute the wafer calibration method based on machine vision provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0139] In the technical solution of this application, the acquisition, storage, use, processing, etc. of data all comply with the relevant regulations of national laws and regulations and do not violate public order and good customs.

[0140] Embodiment 4

[0141] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0142] Figure 5 FIG. shows a schematic structural diagram of an electronic device 10 that can be used to implement the embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as, for example, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, for example, personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0143] As Figure 5 shown, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. Among them, the memory stores a computer program executable by the at least one processor, and the processor 11 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14.

[0144] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disc, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0145] The processor 11 may be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method of wafer calibration based on machine vision.

[0146] In some embodiments, the method of wafer calibration based on machine vision may be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method of wafer calibration based on machine vision described above may be executed. Alternatively, in other embodiments, the processor 11 may be configured to execute the method of wafer calibration based on machine vision by any other suitable means (e.g., by means of firmware).

[0147] The various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor, that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0148] The computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to the processors of general-purpose computers, special-purpose computers, or other programmable data processing devices, such that when the computer programs are executed by the processors, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0149] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0150] To provide for interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can also be used to provide for interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic, speech, or tactile input).

[0151] The systems and techniques described herein can be implemented in a computing system including a back-end component (e.g., as a data server), or a computing system including a middleware component (e.g., an application server), or a computing system including a front-end component (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of a communication network include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0152] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The relationship between the client and the server is created by computer programs running on respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, and solves the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0153] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and this is not limited herein.

[0154] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wafer calibration method based on machine vision, characterized in that, The method includes: Determining the center position of the tray rotation according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray; Placing the target wafer within the reference circle scale line on the tray, and performing image acquisition on the tray to obtain a target image; Based on the target image, determining the center position of the wafer according to the distance between the reference circle scale line and the target wafer; Based on the target image, determining the wafer offset angle according to the reference circle scale line, the center position of the wafer, and the wafer notch identification information; Performing position calibration on the test points on the target wafer according to the center position of the tray rotation, the center position of the wafer, and the wafer offset angle; Wherein, based on the target image, determining the center position of the wafer according to the distance between the reference circle scale line and the target wafer includes: According to the recognition result of the target image, determining the maximum distance and the minimum distance between the reference circle scale line and the target wafer; According to the connection line between the reference circle scale line corresponding to the maximum distance and the target wafer, determining the maximum distance point on the target wafer; According to the connection line between the reference circle scale line corresponding to the minimum distance and the target wafer, determining the minimum distance point on the target wafer; Determining the center position of the wafer according to the maximum distance point and the minimum distance point; Wherein, performing position calibration on the test points on the target wafer according to the center position of the tray rotation, the center position of the wafer, and the wafer offset angle includes: Determining the initial test point position of the test points on the target wafer; Determining the center point offset according to the center position of the tray rotation and the center position of the wafer; Performing position calibration on the initial test point position according to the center point offset and the wafer offset angle to obtain a calibrated test point position; Wherein, performing position calibration on the initial test point position according to the center point offset and the wafer offset angle based on the following formula includes: ； Among them, is the position of the initial test point, is the position of the calibration test point, is the center point offset, is the wafer offset angle.

2. The method according to claim 1, wherein Determining the maximum distance and the minimum distance between the reference circle scale line and the target wafer includes: Traversing each point on the reference circle scale line as a target reference point; Determining the shortest distance between the target reference point and the target wafer, and taking the shortest distance as the target distance between the target reference point and the target wafer; Determining the maximum distance and the minimum distance from the target distances between the target reference point and the target wafer.

3. The method according to claim 1 or 2, characterized in that, Before determining the center position of the wafer according to the maximum distance point and the minimum distance point, the method further includes: Determining whether the maximum distance point is located at the wafer notch position; If so, re-determining the maximum distance point; Correspondingly, after determining the center position of the wafer according to the maximum distance point and the minimum distance point, the method further includes: Determining the position offset between the center position of the wafer and the center position of the tray rotation; If the position offset is greater than a preset offset threshold, re-executing the operation of placing the target wafer within the reference circle scale line on the tray to re-calibrate the target wafer.

4. The method according to claim 1, wherein Wherein, The reference circle scale line includes two vertical positioning points, and the line connecting the two vertical positioning points passes through the center of the tray; Correspondingly, placing the target wafer within the reference circle scale line on the tray includes: Based on the notch of the target wafer with the target vertical positioning point as a reference point, placing the target wafer on the tray; wherein, the target vertical positioning point is the lower vertical positioning point among the two vertical positioning points; Correspondingly, based on the target image, determining the wafer offset angle according to the reference circle scale line, the position of the wafer center, and the wafer notch identification information includes: Determining the position of the wafer notch according to the wafer notch identification information of the target image; Determining the target positioning line according to the positions of the two vertical positioning points on the reference circle scale line; Determining the offset line according to the position of the wafer center and the position of the wafer notch; Determining the angle between the target positioning line and the offset line as the wafer offset angle.

5. The method according to claim 1, characterized in that, Determining the position of the tray rotation center according to the tray image obtained by the rotation of the motor includes: Collecting the first tray image corresponding to the motor rotating by a first angle, performing tray position fitting according to the first tray image, and determining the first tray center position according to the fitting result; Collecting the second tray image corresponding to the motor rotating by a second angle, performing tray position fitting according to the second tray image, and determining the second tray center position according to the fitting result; wherein, the difference between the second angle and the first angle is a preset angle; Determining the position of the tray rotation center according to the first tray center position, the second tray center position, and the preset angle.

6. A wafer calibration device based on machine vision, characterized in that, The device includes: A rotation center determination module, configured to determine the position of the tray rotation center according to the tray image obtained by the rotation of the motor; wherein, a reference circle scale line with a radius greater than the radius of the target wafer is engraved on the tray; A wafer image acquisition module, configured to place the target wafer within the reference circle scale line on the tray and perform image acquisition on the tray to obtain a target image; A wafer center position determination module, configured to determine the position of the wafer center based on the target image according to the distance between the reference circle scale line and the target wafer; A wafer offset angle determination module, configured to determine the wafer offset angle based on the target image according to the reference circle scale line, the position of the wafer center, and the wafer notch identification information; A position calibration module, configured to calibrate the position of the test point on the target wafer according to the position of the tray rotation center, the position of the wafer center, and the wafer offset angle; Among them, the wafer center position determination module includes: A distance determination unit, configured to determine the maximum distance and the minimum distance between the reference circle scale line and the target wafer according to the recognition result of the target image; A first distance point determination unit, configured to determine the maximum distance point on the target wafer according to the connection line between the reference circle scale line corresponding to the maximum distance and the target wafer; A second distance point determination unit, configured to determine the minimum distance point on the target wafer according to the connection line between the reference circle scale line corresponding to the minimum distance and the target wafer; A center position determination unit for determining the center position of the wafer according to the maximum distance point and the minimum distance point; Among them, the position calibration module is specifically used for: Determining the initial test point position of the test points on the target wafer; Determining the center point offset according to the tray rotation center position and the wafer center position; Performing position calibration on the initial test point position according to the center point offset and the wafer offset angle to obtain a calibrated test point position; Among them, performing position calibration on the initial test point position according to the center point offset and the wafer offset angle based on the following formula includes: ； Among them, is the position of the initial test point, is the position of the calibration test point, is the center point offset, is the wafer offset angle.

7. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the machine vision-based wafer calibration method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a processor to execute the machine vision-based wafer calibration method according to any one of claims 1-5 when executed.

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