Wafer calibration method and device based on machine vision, equipment and medium

Abstract

The invention discloses a wafer calibration method and device based on machine vision, equipment and a medium. The method comprises the following steps: determining a tray rotation center position according to a tray image obtained by motor rotation; wherein a reference circle scale line of which the radius is greater than that of a target wafer is engraved on the tray; placing a target wafer in the reference circle scale line on the tray, and performing image acquisition on the tray to obtain a target image; determining the circle center position of the wafer according to the distance between the reference circle scale line and the target wafer based on the target image; based on the target image, determining a wafer deviation angle according to the reference circle scale line, the wafer center position and the wafer gap identification information; and according to the rotation center position of the tray, the circle center position of the wafer and the deviation angle of the wafer, carrying out position calibration on the test point on the target wafer. According to the invention, the wafer calibration efficiency is improved, and the operation of repeatedly taking the wafer from the wafer carrier to the wafer calibrator and then to the process position during wafer calibration is avoided.

Description

Technical Field

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

[0002] Four-probe resistance measuring instruments are used in the field of semiconductor processes to measure the sheet resistance or resistivity of thin films such as implantation, diffusion, epitaxy, and metal coating. Fully automatic four-probe resistance measuring instruments are generally composed of a wafer carrier, a manipulator, a wafer calibrator, and a measurement part. Since there is a certain gap between the wafers placed in the wafer carrier, the wafer edge missing (or notch) is also random, and the wafer operation at the process position needs to be accurate to the specific position. In order to ensure the accuracy of the wafer operation at the process position, the wafer center point and the edge missing (or notch) need to be calibrated.

[0003] The existing technology uses the wafer calibrator in the fully automatic four-probe resistance measuring instrument to calibrate the position of the wafer. The wafer calibrator is a device for locating the center of the wafer and the missing edge (or notch) of the wafer. The robot in the fully automatic four-probe resistance measuring instrument places the wafer on the wafer calibrator, and the wafer calibrator rotates. By identifying the position of the missing edge (or notch) of the wafer, the center point deviation and the direction of the missing edge (or notch) of the wafer are adjusted. The robot takes the wafer from the wafer calibrator again and places it on the process position. After the wafer is finished working on the process position, the robot takes the wafer from the process position again and puts it back to 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 back to the process position. The operation from calibration to work is smooth and complicated, which affects the utilization efficiency of the wafer. 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 fetch the wafer from a wafer carrier to a wafer calibrator and then to a process position during wafer calibration.

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

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

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

[0008] 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;

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

[0010] The position of the test point on the target wafer is calibrated according to the rotation center position of the tray, the center position of the wafer 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, comprising:

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

[0013] A wafer image acquisition module is used to place a target wafer within the reference circle scale line on the tray and acquire an image of the tray to obtain a target image;

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

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

[0016] The position calibration module is used to calibrate the position of the test point on the target wafer according to the rotation center position of the tray, the center position of the wafer and the wafer offset angle.

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

[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 described in any embodiment of the present invention.

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

[0022] The embodiment of the present invention realizes wafer calibration through simple machine vision operations, thereby improving the calibration accuracy of the wafer and reducing the efficiency of wafer calibration, avoiding the need to repeatedly take the wafer from the process position to the calibrator when calibrating the wafer, and reducing the calibration operation process; directly calibrating the wafer at the process position also reduces the space required for wafer calibration.

[0023] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended 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 briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0026] Figure 2 is a flow chart of another wafer calibration method based on machine vision provided according to the first embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the reference circle scale lines and vertical positioning points;

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

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

[0030] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

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

[0032] Embodiment 1

[0033] Figure 1 A flowchart of a wafer calibration method based on machine vision is provided for the first embodiment of the present invention. This embodiment is applicable to the case of calibrating the center position and notch angle of a wafer. The method can be performed 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. The wafer calibration device based on machine vision can be configured in a device with computing capabilities. Figure 1 As shown, the method includes:

[0034] S110 , determining the rotation center position of the pallet according to the pallet 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 used to place wafers on the wafer process position, and the wafers are operated on the process position. The motor refers to the control device that rotates the tray. The tray is rotated by the motor to adjust the position of the wafer on the tray.

[0037] Since the motor drives the pallet to rotate, and the pallet is fixed on the motor's rotating shaft through structural parts, the pallet center and the pallet rotation center are not in the same position due to the installation clearance and installation error, and there is an error. Therefore, in order to ensure the accuracy of subsequent calibration, the deviation between the pallet center and the pallet rotation center needs to be calibrated.

[0038] Specifically, the position of the rotation center of the pallet is determined according to the position change information of the center of the pallet when the motor rotates, wherein the center of the pallet can be determined by a fixed reference center point mark on the pallet, or by a circle fitting result of the pallet.

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

[0040] In a feasible embodiment, S110 includes:

[0041] Acquire a first pallet image corresponding to when the motor rotates by a first angle, perform pallet position fitting according to the first pallet image, and determine the center position of the first pallet according to the fitting result;

[0042] Acquire a second pallet image corresponding to when the motor rotates by a second angle, perform pallet position fitting according to the second pallet image, and determine the center position of the second pallet according to the fitting result; wherein the difference between the second angle and the first angle is a preset angle;

[0043] The rotation center position of the tray is determined according to the center position of the first tray, the center position of the second tray 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, so as to perform visual calibration based on 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 to fill in the light during image acquisition to ensure the clarity of the image.

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

[0046] Exemplarily, when the motor is rotated at 0 degrees, an image of the pallet is captured once to obtain a first pallet image, a circle fitting is performed on the pallet in the first pallet image, and the center position of the circle fitting result is the first pallet center position p1 (p1.x, p1.y); similarly, when the motor is rotated at 180 degrees, an image of the pallet is captured once to obtain a second pallet image, a circle fitting is performed on the pallet in the second pallet image, and the center position of the circle fitting result is the second pallet center position p2 (p2.x, p2.y), then the pallet rotation center position p((p1.x+p2.x) / 2, (p1.y+p2.y) / 2). Similarly, other preset angles can be inferred based on the positional relationship, which is not limited here. Optionally, multiple sets of preset angles can be used to obtain multiple pallet rotation center positions to ensure the accuracy of the determination of the pallet rotation center position.

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

[0048] The robot is controlled to operate so as to place the target wafer within the reference circle scale line. For example, the position movement information of the robot is determined according to the position information of the robot, 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 so as to control the target wafer to be placed within the reference circle scale line on the tray. Alternatively, the target wafer is controlled to be placed within the reference circle scale line on the tray by the image recognition result acquired by the image acquisition device. After the target wafer is placed, the tray is photographed to obtain the target image.

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

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

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

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

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

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

[0055] Specifically, the center point offset is determined according to the rotation center position of the tray and the center position of the wafer, and then the initial test point position is calibrated according to the center point offset and the wafer offset angle, and the point position of the rotary motor and the linear motion motor is calculated according to the calibrated test point position. Exemplarily, the multiple test points include a test sequence, and the point position calculation is performed in sequence according to the test sequence.

[0056] Among them, the position of the test point on the target wafer is calibrated according to the rotation center position of the tray, the center position of the wafer, 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] Wherein, (x1, y1) is the initial test point position of the test point on the target wafer, (x1, y1) is the calibration 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 wafer calibration through simple machine vision operations, thereby improving the calibration accuracy of the wafer and reducing the efficiency of wafer calibration, avoiding the need to repeatedly take the wafer from the process position to the calibrator when calibrating the wafer, and reducing the calibration operation process; directly calibrating the wafer at the process position also reduces the space required for wafer calibration.

[0061] Embodiment 2

[0062] Figure 2 This is a flowchart of a wafer calibration method based on machine vision provided in the second embodiment of the present invention. This embodiment further refines the technical solution in the above embodiment. Figure 2 As shown, the method includes:

[0063] S210 , determining the rotation center position of the pallet according to the pallet image obtained by the rotation of the motor.

[0064] Among them, a reference circle scale line with a radius larger than the radius of the target wafer is engraved on the tray. 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.

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

[0066] S220, placing the target wafer on a tray based on the notch of the target wafer and taking the target vertical positioning point as a reference point, and performing image acquisition on the tray to obtain a target image.

[0067] The target vertical positioning point is the lower vertical positioning point among the two vertical positioning points.

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

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

[0070] The target wafer is located within the reference circle scale line. The distance between each point on the reference circle scale line and the target wafer is determined in turn, and the maximum distance and the minimum distance are determined. 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. Figure 3 Point E is the maximum distance point, and point F is the minimum distance point. According to the characteristics of the circle, the line connecting the maximum distance point and the minimum distance point passes through the center of the circle, that is, the line connecting the maximum distance point and the minimum distance point is the diameter of the target wafer. The center position of the wafer is determined based on half of the value of the sum of the position information of the maximum distance point and the minimum distance point.

[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 as the target reference point;

[0073] 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;

[0074] A maximum distance and a minimum distance are determined from the target distances between the target reference point and the target wafer.

[0075] Determine the distance between each point on the reference circle scale line and the target wafer respectively. When determining a certain point, this point is used 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 the target reference point and the target wafer. The target distance between each point on the reference circle scale line and the target wafer is obtained, and they are sorted according to the target distance to obtain the maximum distance and the minimum distance.

[0076] In a feasible embodiment, before determining the center position of the wafer 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 at, redetermine the maximum distance point;

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

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

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

[0082] Specifically, after determining the maximum distance point on the target wafer, it is determined 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, the maximum distance point is judged. If it is located, the maximum distance point is re-determined.

[0083] Similarly, in order to avoid the problem of recognition error based on the wafer notch position, and to avoid the maximum distance point falling exactly on the wafer notch position when placing the wafer, after determining the wafer center position based on the maximum distance point and the minimum distance point, the position offset between the wafer center position and the tray rotation center position is determined. If the position offset is large, it proves that the wafer center position is incorrectly determined, that is, the maximum distance point and the minimum distance point are not accurately positioned. The target wafer is then re-placed and the calibration process is re-executed to improve the accuracy of the wafer center position determination.

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

[0085] According to the wafer notch feature, the target image is recognized to obtain the wafer notch position. If the wafer notch is an area, the center point of the notch area is used as the wafer notch position. Connect the positions of the two vertical positioning points on the reference circle scale line as the target positioning line, connect the wafer center position and the wafer notch position as the offset line, and determine the angle between the target positioning line and the offset line as the wafer offset angle. Similarly, if Figure 3 As shown, the reference circle scale line may also include a horizontal positioning point at point B, so as to determine the horizontal target positioning line and the wafer offset angle according to the horizontal positioning point.

[0086] S250, determining the initial test point position of the test point on the target wafer; determining the center point offset according to the tray rotation center position and the wafer center position; calibrating the initial test point position according to the center point offset and the wafer offset angle to obtain the calibrated test point position.

[0087] A unified coordinate system is established based on the image acquisition device. All positions in the embodiment of the present invention are in the same coordinate system to ensure the accuracy of position information determination and improve calculation efficiency. The test points on the target wafer are determined, and the initial test point positions of each test point in the camera coordinate system are determined. The center point offset is determined based on the rotation center position of the tray and the center position of the wafer. The initial test point position is calibrated based on the center point offset and the wafer offset angle to obtain the calibration test point position. The motion control of the motor shaft is performed based on the calibration test point position.

[0088] The position of the initial test point is calibrated 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] Wherein, (x1, y1) is the initial test point position, (x1, y1) is the calibration 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 by judging the center position of the wafer and calibrating other machine vision angles, thereby improving the calibration accuracy.

[0093] Embodiment 3

[0094] Figure 4The schematic diagram of the structure of a wafer calibration device based on machine vision provided in the third embodiment of the present invention. Figure 4 As shown, the device comprises:

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

[0096] The wafer image acquisition module 420 is used to place the target wafer within the reference circle scale line on the tray and acquire the image of the tray to obtain the target image;

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

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

[0099] The position calibration module 450 is used to calibrate the position of the test point on the target wafer according to the rotation center position of the tray, the center position of the wafer and the wafer offset angle.

[0100] The embodiment of the present invention realizes wafer calibration through simple machine vision operations, thereby improving the calibration accuracy of the wafer and reducing the efficiency of wafer calibration, avoiding the need to repeatedly take the wafer from the process position to the calibrator when calibrating the wafer, and reducing the calibration operation process; directly calibrating the wafer at the process position also reduces the space required for wafer calibration.

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

[0102] A distance determination unit, used 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 a maximum distance point on the target wafer according to a 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 a minimum distance point on the target wafer according to a line between the reference circle scale line corresponding to the minimum distance and the target wafer;

[0105] A center position determining unit is used to determine the center position of the wafer according to the maximum distance point and the minimum distance point.

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

[0107] Traversing each point on the reference circle scale as a 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] A maximum distance and a minimum distance are determined from target distances between the target reference point and the target wafer.

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

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

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

[0113] If it is located at, redetermine the maximum distance point;

[0114] Accordingly, the device further includes a position offset determination module, which is used to:

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

[0116] Determining a position offset between the wafer center position and the tray rotation center position;

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

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

[0119] Correspondingly, the wafer image acquisition module is specifically used for:

[0120] Based on the notch of the target wafer and taking the target vertical positioning point as a reference point, the target wafer is placed on the tray; wherein the target vertical positioning point is the lower vertical positioning point of the two vertical positioning points;

[0121] Accordingly, the wafer offset angle determination module is specifically used for:

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

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

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

[0125] An angle between the target positioning line and the offset line is determined as the wafer offset angle.

[0126] Optional, position calibration module, specifically used for:

[0127] Determining initial test point positions of test points on the target wafer;

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

[0129] Calibrate the initial test point position according to the center point offset and the wafer offset angle to obtain a calibrated test point position;

[0130] The initial test point position is calibrated according to the center point offset and the wafer offset angle based on the following formula, including:

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

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

[0133] Wherein, (x1, y1) is the initial test point position, (x1, y1) is the calibration 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 used for:

[0135] Acquire a first pallet image corresponding to when the motor rotates by a first angle, perform pallet position fitting according to the first pallet image, and determine the center position of the first pallet according to the fitting result;

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

[0137] The rotation center position of the tray is determined according to the center position of the first tray, the center position of the second tray and a preset angle.

[0138] The machine vision-based wafer calibration device provided in the embodiment of the present invention can execute the machine vision-based wafer calibration method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0139] The acquisition, storage, use, and processing of data in the technical solution of this application comply with the relevant provisions of national laws and regulations and do not violate public order and good morals.

[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 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as 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 personal digital processing, 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 examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0143] like Figure 5 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform 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 to 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. An input / output (I / O) interface 15 is also connected to the bus 14.

[0144] A number 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 disk, an optical disk, 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 a variety of general and / or special 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 appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method for wafer calibration based on machine vision.

[0146] In some embodiments, the method of wafer calibration based on machine vision can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on 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 can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the method of wafer calibration based on machine vision in any other appropriate manner (for example, by means of firmware).

[0147] Various implementations 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 reference products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being 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 data and instructions to the storage system, the at least one input device, and the at least one output device.

[0148] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0149] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0150] To provide interaction with a user, the systems and techniques described herein may 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 trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0151] The systems and techniques described herein may be implemented in a computing system that includes a backend component (e.g., as a data server), or a computing system that includes a switch component (e.g., an application server), or a computing system that includes a frontend component (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such backend components, switch components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks 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 remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0153] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0154] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wafer calibration method based on machine vision, characterized in that: The method includes: Determine the rotation center position of the tray according to the tray image obtained by the rotation of the motor; wherein the tray is engraved with a reference circle scale line whose radius is larger than the radius of the target wafer; Placing a target wafer within the reference circle scale line on a tray, and acquiring 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 a wafer offset angle according to the reference circle scale lines, the wafer center position, and wafer notch identification information; The position of the test point on the target wafer is calibrated according to the rotation center position of the tray, the center position of the wafer and the wafer offset angle.

2. The method according to claim 1, characterized in that 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, including: Determining a maximum distance and a minimum distance between the reference circle scale line and the target wafer according to a recognition result of the target image; Determining a maximum distance point on the target wafer according to a line between the reference circle scale line corresponding to the maximum distance and the target wafer; Determining a minimum distance point on the target wafer according to a line between the reference circle scale line corresponding to the minimum distance and the target wafer; The center position of the wafer is determined according to the maximum distance point and the minimum distance point.

3. The method according to claim 2, characterized in that Determining a maximum distance and a minimum distance between the reference circle scale line and the target wafer includes: Traversing each point on the reference circle scale as a target reference point; 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; A maximum distance and a minimum distance are determined from target distances between the target reference point and the target wafer.

4. The method according to claim 2 or 3, 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 it is located at, redetermine 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 a position offset between the wafer center position and the tray rotation center position; If the position offset is greater than a preset offset threshold, the operation of placing the target wafer within the reference circle scale line on the tray is re-executed to recalibrate the target wafer.

5. The method according to claim 1, characterized in that in, 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 pallet; Accordingly, placing the target wafer within the reference circle scale line on the tray includes: Based on the notch of the target wafer and taking the target vertical positioning point as a reference point, the target wafer is placed on the tray; wherein the target vertical positioning point is the lower vertical positioning point of the two vertical positioning points; Accordingly, based on the target image, determining the wafer offset angle according to the reference circle scale lines, the wafer center position and the wafer notch identification information includes: Determine the wafer notch position according to the wafer notch identification 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 an offset line according to the wafer center position and the wafer notch position; An angle between the target positioning line and the offset line is determined as the wafer offset angle.

6. The method according to claim 1, characterized in that Calibrate the position of the test point on the target wafer according to the rotation center position of the tray, the center position of the wafer, and the wafer offset angle, including: Determining initial test point positions of test points on the target wafer; Determine the center point offset according to the rotation center position of the tray and the center position of the wafer; Calibrate the initial test point position according to the center point offset and the wafer offset angle to obtain a calibrated test point position; The initial test point position is calibrated according to the center point offset and the wafer offset angle based on the following formula, including: x2=(x1+dx)*cos(θ)+(y1+dy)*sin(θ) y2=-(x1+dx)*sin(θ)+(y1+dy)*cos(θ); Wherein, (x1, y1) is the initial test point position, (x1, y1) is the calibration test point position, (dx, dy) is the center point offset, and θ is the wafer offset angle.

7. The method according to claim 1, characterized in that The center position of the pallet rotation is determined based on the pallet image obtained by the motor rotation, including: Acquire a first pallet image corresponding to when the motor rotates by a first angle, perform pallet position fitting according to the first pallet image, and determine the center position of the first pallet according to the fitting result; Acquire a second pallet image corresponding to when the motor rotates a second angle, perform pallet position fitting according to the second pallet image, and determine the center position of the second pallet according to the fitting result; wherein the difference between the second angle and the first angle is a preset angle; The rotation center position of the tray is determined according to the center position of the first tray, the center position of the second tray and the preset angle.

8. A wafer calibration device based on machine vision, characterized in that: The device includes: A rotation center determination module, used to determine the rotation center position of the tray according to the tray image obtained by the rotation of the motor; wherein the tray is engraved with a reference circle scale line whose radius is larger than the radius of the target wafer; A wafer image acquisition module is used to place a target wafer within the reference circle scale line on the tray and acquire an image of the tray to obtain a target image; A wafer center position determination module, used to determine the wafer center position based on the target image and the distance between the reference circle scale line and the target wafer; A wafer offset angle determination module is used to determine the wafer offset angle based on the target image, according to the reference circle scale lines, the wafer center position and wafer notch identification information; The position calibration module is used to calibrate the position of the test point on the target wafer according to the rotation center position of the tray, the center position of the wafer and the wafer offset angle.

9. An electronic device, characterized in that: The electronic device comprises: 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 perform the machine vision-based wafer calibration method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the machine vision-based wafer calibration method according to any one of claims 1 to 7 when executed.

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