Correction method and correction jig of wafer positioning system

Abstract

The invention relates to wafer positioning, in particular to a wafer positioning system correction method and a correction jig, the correction jig is placed in a mechanical gripper, and it is ensured that the correction jig is located in the detection range of a position detection device on the mechanical gripper; the correction jig is translated, so that a positioning point on the edge of the correction jig is moved to a position detection device; calculating an inclination angle between the position detection device and the horizontal line by using the geometrical relationship; determining the actual coordinate of the circle center of the wafer according to the inclination angle between the position detection device and the horizontal line; according to the technical scheme provided by the invention, the defect that the actual coordinate of the circle center of the wafer is difficult to accurately, conveniently and quickly determine in the prior art can be effectively overcome.

Description

Technical Field

[0001] The present invention relates to wafer positioning, and in particular to a correction method and a correction jig of a wafer positioning system. Background Art

[0002] During wafer transfer, many factors can cause wafer position deviation, such as pin lift and hot plate limiter. Wafer position deviation can prevent the robotic gripper from properly handling wafers. Severe accumulated errors can lead to serious failures such as wafer breakage. Traditional support-type robotic grippers typically utilize a trapezoidal opening, allowing the wafer to slide down the surrounding slope to the bottom, ensuring correct wafer position deviation with each transfer.

[0003] However, wafer size tolerances and machining precision limits combine to guarantee only ±0.15mm accuracy. In recent years, the demand for high EBR accuracy has led to increasingly stringent requirements for wafer positioning accuracy. For example, the current KrF process requires an EBR accuracy of 0.2mm. Considering the robot's transmission accuracy of only 0.1mm at best, this, combined with the robot's gripper accuracy of 0.15mm, clearly cannot meet the EBR accuracy requirement.

[0004] Furthermore, for specialized processes like edge coating (applying adhesive to the wafer edge), using a traditional support-type gripper can cause the wafer edge to rub against the gripper as it slides, leading to peeling of the edge adhesive and the appearance of defects such as particles. Consequently, vacuum chuck grippers have become increasingly popular as a non-contact solution for compensating for wafer position deviations, using optical systems and other methods.

[0005] like Figure 14 As shown, in the prior art, four position detection devices are usually used to determine the four points of the wafer, thereby determining the actual position of the wafer center, and then judging the deviation between the actual position of the wafer and the target position. Since the calculation method is pre-designed, this method requires extremely high installation accuracy of the position detection device. If there is a deviation in the installation position (such as an angle offset), the actual position of the wafer calculated according to the preset calculation method will produce a certain degree of deviation, resulting in calculation errors. In fact, there will inevitably be errors in processing and installation, so the correction accuracy of the prior art is difficult to guarantee. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a correction method and a correction fixture for a wafer positioning system, which can effectively overcome the defect of the prior art that it is difficult to accurately, conveniently and quickly determine the actual coordinates of the wafer center.

[0008] (2) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] A method for calibrating a wafer positioning system comprises the following steps:

[0011] S1. Place the calibration jig in the robotic gripper and ensure that the calibration jig is within the detection range of the position detection device on the robotic gripper;

[0012] S2. The calibration jig is translated so that the positioning point on the edge of the calibration jig moves to the position detection device;

[0013] S3. Calculate the inclination angle between the position detection device and the horizontal line using geometric relationships;

[0014] S4. Determine the actual coordinates of the center of the wafer based on the inclination angle between the position detection device and the horizontal line;

[0015] Herein, the positioning point of the edge of the correction jig is moved to the position detection device.

[0016] Preferably, calculating the inclination angle between the position detection device and the horizontal line using a geometric relationship in S3 includes:

[0017] S31, make auxiliary lines;

[0018] S32. Calculate the angle between line segment a and line segment b;

[0019] S33, calculating the length of line segment c;

[0020] S34, calculating the angle between line segment b and line segment c;

[0021] S35, calculating the angle between line segment c and line segment d;

[0022] S36. Calculate the angle between line segment f and line segment g.

[0023] Preferably, making auxiliary lines in S31 includes:

[0024] Connect the centers of the circles before and after the movement of the correction fixture, set as line segment a;

[0025] Connect the target positioning point and the center of the circle of the calibration fixture after movement, set as line segment b;

[0026] Connect the target positioning point and the center of the circle of the calibration fixture before moving, set as line segment c;

[0027] The intersection between the position detection device and the edges of the correction fixture before and after movement is set as line segment d;

[0028] Connect the intersection of the position detection device, the edge of the pre-movement correction jig, and the center of the pre-movement correction jig to form a line segment e;

[0029] Draw an extension line of the position detection device and a horizontal line passing through the center of the circle of the front and rear correction jigs. Connect the intersection of the extension line and the horizontal line with the intersection of the position detection device and the edge of the correction jig before moving, and set it as line segment f. Connect the intersection of the extension line and the horizontal line with the center of the circle of the correction jig before moving, and set it as line segment g.

[0030] Preferably, calculating the angle between line segment a and line segment b in S32 includes:

[0031] The angle α between the line connecting the positioning point on the edge of the calibration jig and the center of the calibration jig and the horizontal line is an acute angle.

[0032] When the target positioning point is located to the right of the center of the circle of the calibration jig before movement and the calibration jig is translated to the right, and when the target positioning point is located to the left of the center of the circle of the calibration jig before movement and the calibration jig is translated to the left, the angle ∠ab between line segment a and line segment b is 180°-α;

[0033] When the target positioning point is located to the right of the center of the circle of the correction jig before movement and the correction jig is translated to the left, and when the target positioning point is located to the left of the center of the circle of the correction jig before movement and the correction jig is translated to the right, the angle ∠ab between line segment a and line segment b is α.

[0034] Preferably, the length of line segment c in S33 includes:

[0035] The length of line segment a is the translation distance of the calibration fixture, and the length of line segment b is the radius r of the calibration fixture. Based on line segments a, b, and the included angle ∠ab in the triangle, calculate the length of line segment c.

[0036] Preferably, calculating the angle between line segment b and line segment c in S34 includes:

[0037] Based on line segments a, b, and c in the triangle, calculate the angle ∠bc between line segments b and c.

[0038] Preferably, calculating the angle between line segment c and line segment d in S35 includes:

[0039] The length of line segment d is the moving distance of the calibration fixture on the position detection device, and the length of line segment e is the radius r of the calibration fixture. Based on line segments c, d, and e in the triangle, calculate the angle ∠cd between line segments c and d.

[0040] Preferably, calculating the angle between line segment f and line segment g in S36 includes:

[0041] When the target positioning point is to the right of the center of the calibration jig before movement, the calibration jig is translated to the right, and line segment g is to the right of line segment f, ∠fg + ∠bd = α, so the angle between line segments f and g is ∠fg = α - ∠bd = α - (∠bc + ∠cd);

[0042] When the target positioning point is located to the right of the center of the calibration jig before movement, the calibration jig is translated to the right, and line segment g is to the left of line segment f, ∠fg = α + ∠bd, so the angle between line segments f and g is ∠fg = α + (∠cd - ∠bc);

[0043] When the target positioning point is located to the right of the center of the calibration jig before movement, the calibration jig is translated to the left, and line segment g is to the right of line segment f, ∠fg + ∠ac = ∠cd, ∠ac = 180° - ∠ab - ∠bc, ∠ab = α, so the angle between line segments f and g is ∠fg = α + ∠cd + ∠bc - 180°;

[0044] When the target positioning point is located to the right of the center of the calibration jig before movement, the calibration jig is translated to the left, and line segment g is to the left of line segment f, ∠fg + ∠gc = ∠cd, ∠gc = 180° - ∠ac, ∠ac = 180° - ∠ab - ∠bc, ∠ab = α, so the angle between line segments f and g is ∠fg = ∠cd - ∠bc - α;

[0045] When the target positioning point is located to the lower left of the center of the calibration jig before movement, the calibration jig is translated to the right, and line segment g is to the left of line segment f, ∠fg + ∠gc = ∠cd, ∠gc = ∠ac, ∠ac = 180° - ∠ab - ∠bc, ∠ab = α, so the angle between line segment f and line segment g is ∠fg = α + ∠cd + ∠bc - 180°;

[0046] When the target positioning point is located on the upper left side of the center of the calibration fixture before movement, the calibration fixture is translated to the right, and line segment g is on the left side of line segment f, ∠fg = ∠cd - ∠ac, ∠ac = 180° - ∠ab - ∠bc, ∠ab = α, so the angle between line segments f and g is ∠fg = α + ∠cd + ∠bc - 180°;

[0047] When the target positioning point is located on the upper left side of the center of the calibration jig before movement, the calibration jig is translated to the left, and line segment g is on the right side of line segment f, ∠fg + ∠bd = ∠ab, ∠bd = ∠cd - ∠bc, so the angle between line segments f and g is ∠fg = α + ∠cd - ∠bc;

[0048] When the target positioning point is located on the upper left side of the center of the calibration fixture before movement, the calibration fixture is translated to the left, and line segment g is on the left side of line segment f, ∠fg + ∠ab + ∠bc + ∠cd = 180°, ∠ab = 180° - α, so the angle between line segments f and g is ∠fg = α - ∠bc - ∠cd;

[0049] When the target positioning point is located on the lower right side of the center of the correction jig before movement, the correction jig is translated to the right, and line segment g is on the right side of line segment f, ∠fg+∠ab+∠bc+∠cd=180°, ∠ab=180°-α, so the angle between line segment f and line segment g is ∠fg=α-∠bc-∠cd.

[0050] Preferably, determining the actual coordinates of the center of the wafer according to the inclination angle between the position detection device and the horizontal line in S4 includes:

[0051] A coordinate system is established with the center of the calibration fixture before movement as the origin and the moving direction of the calibration fixture as the horizontal axis. The target positioning point on the edge of the calibration fixture after movement is set as A. The coordinates of point A are (r*cosα+a,r*sinα);

[0052] When in use, the intersection point between the wafer edge and the position detection device is set to B. The distance L between A and B is obtained by multiplying the number of pixels by the pixel size. The coordinates of point B are (r*cosα+a+L*cosθ, r*sinα+L*sinθ). The actual coordinates of the center of the wafer are determined by calculating the coordinates of the four intersection points between the wafer edge and the four position detection devices.

[0053] Where θ is the angle ∠fg between line segments f and g.

[0054] A calibration jig for a wafer positioning system includes a calibration jig of the same size as a wafer and four positioning points arranged on the edge of the calibration jig, wherein the angle α between the line connecting the positioning points on the edge of the calibration jig, the center of the calibration jig, and the horizontal line is α;

[0055] Where α is an acute angle, α∈[40°,70°].

[0056] (3) Beneficial effects

[0057] Compared with the prior art, the present invention provides a correction method and a correction fixture for a wafer positioning system. Even if the position detection device deviates during installation, the reference point can be re-determined. Only the preset calculation data needs to be modified to enable the position detection device to work normally, thus avoiding the need to reinstall the position detection device. The actual coordinates of the wafer center can be determined accurately, conveniently and quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0059] Figure 1 It is a schematic diagram of the process of the present invention;

[0060] Figure 2 Schematic diagram of the structure of the calibration fixture in the present invention;

[0061] Figure 3 This is a first schematic diagram of calculating the angle ∠fg when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the right, and the line segment g is to the right of the line segment f in the present invention;

[0062] Figure 4 This is a second schematic diagram of calculating the angle ∠fg when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the right, and the line segment g is to the right of the line segment f in the present invention;

[0063] Figure 5 Schematic diagram of calculating the angle ∠fg when the target positioning point is located to the right of the center of the circle of the calibration jig before movement, the calibration jig is translated to the right, and the line segment g is to the left of the line segment f in the present invention;

[0064] Figure 6 Schematic diagram of calculating the angle ∠fg when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the left, and the line segment g is to the right of the line segment f in the present invention;

[0065] Figure 7 Schematic diagram of calculating the angle ∠fg when the target positioning point is located to the right of the center of the circle of the calibration jig before movement, the calibration jig is translated to the left, and the line segment g is to the left of the line segment f in the present invention;

[0066] Figure 8 Schematic diagram of calculating the angle ∠fg when the target positioning point is located to the lower left of the center of the correction jig before movement, the correction jig is translated to the right, and the line segment g is to the left of the line segment f in the present invention;

[0067] Figure 9 Schematic diagram of calculating the angle ∠fg when the target positioning point is located on the upper left side of the center of the correction jig before movement, the correction jig is translated to the right, and the line segment g is on the left side of the line segment f in the present invention;

[0068] Figure 10Schematic diagram of calculating the angle ∠fg when the target positioning point is located on the upper left side of the center of the correction jig before movement, the correction jig is translated to the left, and the line segment g is to the right of the line segment f in the present invention;

[0069] Figure 11 Schematic diagram of calculating the angle ∠fg when the target positioning point is located on the upper left side of the center of the correction jig before movement, the correction jig is translated to the left, and the line segment g is on the left side of the line segment f in the present invention;

[0070] Figure 12 Schematic diagram of calculating the angle ∠fg when the target positioning point is located to the lower right of the center of the correction jig before movement, the correction jig is translated to the right, and the line segment g is to the right of the line segment f in the present invention;

[0071] Figure 13 Schematic diagram of determining the coordinates of any point on the position detection device according to the inclination angle between the position detection device and the horizontal line in the present invention;

[0072] Figure 14 This is a schematic diagram of using four position detection devices in the prior art to determine the actual position of the center of a wafer. DETAILED DESCRIPTION

[0073] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0074] A method for calibrating a wafer positioning system, such as Figure 1 As shown, S1, place the calibration jig in the robot gripper and ensure that the calibration jig is within the detection range of the position detection device on the robot gripper;

[0075] S2. The calibration jig is translated so that the positioning point on the edge of the calibration jig moves to the position detection device;

[0076] S3. Calculate the inclination angle between the position detection device and the horizontal line using geometric relationships;

[0077] S4. Determine the actual coordinates of the center of the wafer based on the inclination angle between the position detection device and the horizontal line;

[0078] The positioning point moved to the position detection device is used as the target positioning point.

[0079] ① In S3, the inclination angle between the position detection device and the horizontal line is calculated using geometric relationships, including:

[0080] S31, make auxiliary lines;

[0081] S32. Calculate the angle between line segment a and line segment b;

[0082] S33, calculating the length of line segment c;

[0083] S34, calculating the angle between line segment b and line segment c;

[0084] S35, calculating the angle between line segment c and line segment d;

[0085] S36. Calculate the angle between line segment f and line segment g.

[0086] 1) Make auxiliary lines in S31, such as Figure 3 Shown, including:

[0087] Connect the centers of the circles before and after the movement of the correction fixture, set as line segment a;

[0088] Connect the target positioning point and the center of the circle of the calibration fixture after movement, set as line segment b;

[0089] Connect the target positioning point and the center of the circle of the calibration fixture before moving, set as line segment c;

[0090] The intersection between the position detection device and the edges of the correction fixture before and after movement is set as line segment d;

[0091] Connect the intersection of the position detection device, the edge of the pre-movement correction jig, and the center of the pre-movement correction jig to form a line segment e;

[0092] Draw an extension line of the position detection device and a horizontal line passing through the center of the circle of the front and rear correction jigs. Connect the intersection of the extension line and the horizontal line with the intersection of the position detection device and the edge of the correction jig before moving, and set it as line segment f. Connect the intersection of the extension line and the horizontal line with the center of the circle of the correction jig before moving, and set it as line segment g.

[0093] 2) In S32, the angle between line segment a and line segment b is calculated, such as Figure 3 and Figure 4 Shown, including:

[0094] The angle α between the line connecting the positioning point on the edge of the calibration jig and the center of the calibration jig and the horizontal line is an acute angle.

[0095] When the target positioning point is located to the right of the center of the circle of the calibration jig before movement and the calibration jig is translated to the right, and when the target positioning point is located to the left of the center of the circle of the calibration jig before movement and the calibration jig is translated to the left, the angle ∠ab between line segment a and line segment b is 180°-α;

[0096] When the target positioning point is located to the right of the center of the circle of the correction jig before movement and the correction jig is translated to the left, and when the target positioning point is located to the left of the center of the circle of the correction jig before movement and the correction jig is translated to the right, the angle ∠ab between line segment a and line segment b is α.

[0097] In the technical solution of this application, the calculation results of the angle ∠ab between line segment a and line segment b are shown in the following table:

[0098] Table 1 Calculation results of the angle ∠ab between line segment a and line segment b

[0099]

[0100] 3) The length of line segment c in S33, such as Figure 3 and Figure 4 Shown, including:

[0101] The length of line segment a is the translation distance of the calibration fixture, and the length of line segment b is the radius r of the calibration fixture. Based on line segments a, b, and the included angle ∠ab in the triangle, calculate the length of line segment c.

[0102] 4) In S34, the angle between line segment b and line segment c is calculated, such as Figure 3 and Figure 4 Shown, including:

[0103] Based on line segments a, b, and c in the triangle, calculate the angle ∠bc between line segments b and c.

[0104] 5) In S35, the angle between line segment c and line segment d is calculated, such as Figure 3 and Figure 4 Shown, including:

[0105] The length of line segment d is the distance the calibration jig moves on the position detection device, which is obtained by multiplying the number of pixels the calibration jig moves by the pixel size. The length of line segment e is the radius r of the calibration jig. Based on line segments c, d, and e in the triangle, calculate the angle ∠cd between line segments c and d.

[0106] 6) Calculating the angle between line segment f and line segment g in S36 includes:

[0107] like Figure 3 and Figure 4 As shown, when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig translates to the right, and line segment g is to the right of line segment f, ∠fg + ∠bd = α, so the angle between line segment f and line segment g is ∠fg = α - ∠bd = α - (∠bc + ∠cd);

[0108] like Figure 5As shown, when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the right, and line segment g is to the left of line segment f, ∠fg = α + ∠bd, so the angle between line segment f and line segment g is ∠fg = α + (∠cd - ∠bc);

[0109] like Figure 6 As shown in the figure, when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the left, and line segment g is to the right of line segment f, ∠fg+∠ac=∠cd, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle between line segment f and line segment g is ∠fg=α+∠cd+∠bc-180°;

[0110] like Figure 7 As shown in the figure, when the target positioning point is located to the right of the center of the correction jig before movement, the correction jig is translated to the left, and line segment g is to the left of line segment f, ∠fg+∠gc=∠cd, ∠gc=180°-∠ac, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle between line segment f and line segment g is ∠fg=∠cd-∠bc-α;

[0111] like Figure 8 As shown, when the target positioning point is located on the lower left side of the center of the correction jig before movement, the correction jig is translated to the right, and line segment g is on the left side of line segment f, ∠fg+∠gc=∠cd, ∠gc=∠ac, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle between line segment f and line segment g is ∠fg=α+∠cd+∠bc-180°;

[0112] like Figure 9 As shown, when the target positioning point is located on the upper left side of the center of the correction jig before movement, the correction jig is translated to the right, and line segment g is on the left side of line segment f, ∠fg = ∠cd - ∠ac, ∠ac = 180° - ∠ab - ∠bc, ∠ab = α, so the angle between line segment f and line segment g is ∠fg = α + ∠cd + ∠bc - 180°;

[0113] like Figure 10 As shown in the figure, when the target positioning point is located on the upper left side of the center of the correction fixture before movement, the correction fixture is translated to the left, and the line segment g is on the right side of the line segment f, ∠fg+∠bd=∠ab, ∠bd=∠cd-∠bc, so the angle between the line segment f and the line segment g is ∠fg=α+∠cd-∠bc;

[0114] like Figure 11As shown in the figure, when the target positioning point is located on the upper left side of the center of the correction fixture before movement, the correction fixture is translated to the left, and line segment g is on the left side of line segment f, ∠fg+∠ab+∠bc+∠cd=180°, ∠ab=180°-α, so the angle between line segment f and line segment g is ∠fg=α-∠bc-∠cd;

[0115] like Figure 12 As shown, when the target positioning point is located on the lower right side of the center of the correction jig before movement, the correction jig is translated to the right, and line segment g is on the right side of line segment f, ∠fg+∠ab+∠bc+∠cd=180°, ∠ab=180°-α, so the angle between line segment f and line segment g is ∠fg=α-∠bc-∠cd.

[0116] In the technical solution of this application, the calculation results of the angle ∠fg between line segment f and line segment g are shown in the following table:

[0117] Table 2 Calculation results of the angle ∠fg between line segments f and g

[0118]

[0119] ② In S4, the actual coordinates of the center of the wafer are determined based on the inclination angle between the position detection device and the horizontal line, such as Figure 13 Shown, including:

[0120] A coordinate system is established with the center of the calibration fixture before movement as the origin and the moving direction of the calibration fixture as the horizontal axis. The target positioning point on the edge of the calibration fixture after movement is set as A. The coordinates of point A are (r*cosα+a,r*sinα);

[0121] When in use, the intersection point between the wafer edge and the position detection device is set to B. The distance L between A and B is obtained by multiplying the number of pixels by the pixel size. The coordinates of point B are (r*cosα+a+L*cosθ, r*sinα+L*sinθ). The actual coordinates of the center of the wafer are determined by calculating the coordinates of the four intersection points between the wafer edge and the four position detection devices.

[0122] Where θ is the angle ∠fg between line segments f and g.

[0123] On the basis of the calibration method of the wafer positioning system disclosed above, the technical solution of the present application further discloses a calibration jig of the wafer positioning system, such as Figure 2 As shown, it includes a calibration jig of the same size as the wafer and four positioning points set on the edge of the calibration jig, and the angle between the line connecting the positioning points on the edge of the calibration jig, the center of the calibration jig and the horizontal line is α;

[0124] Where α is an acute angle, α∈[40°,70°].

[0125] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A calibration method for a wafer positioning system, characterized in that: The following steps are involved: S1. Place the calibration jig in the robot gripper and ensure that the calibration jig is within the detection range of the position detection device on the robot gripper; S2, translating the calibration jig so that the positioning point on the edge of the calibration jig moves to the position detection device; S3, calculating the inclination angle between the position detection device and the horizontal line using geometric relationships; S4, determining the actual coordinates of the center of the wafer according to the inclination angle between the position detection device and the horizontal line; The positioning point moved to the position detection device is used as the target positioning point.

2. The calibration method of the wafer positioning system according to claim 1, characterized in that: In S3, the inclination angle between the position detection device and the horizontal line is calculated by using the geometric relationship, including: S31, make auxiliary lines; S32, calculating the angle between line segment a and line segment b; S33, calculating the length of line segment c; S34, calculating the angle between line segment b and line segment c; S35, calculating the angle between line segment c and line segment d; S36. Calculate the angle between line segment f and line segment g.

3. The calibration method of the wafer positioning system according to claim 2, characterized in that: Auxiliary lines in S31 include: Connect the centers of the circles of the calibration fixtures before and after the movement, set as line segment a; Connect the target positioning point and the center of the circle of the calibration fixture after movement, set as line segment b; Connect the target positioning point and the center of the circle of the calibration fixture before moving, set as line segment c; The intersection between the position detection device and the edges of the correction jig before and after the movement is connected, and is set as line segment d; Connect the intersection of the position detection device, the edge of the pre-movement correction jig, and the center of the pre-movement correction jig to set it as a line segment e; Draw an extension line of the position detection device and a horizontal line passing through the center of the circle of the front and rear correction jigs. Connect the intersection of the extension line and the horizontal line with the intersection of the position detection device and the edge of the front correction jig, set it as line segment f. Connect the intersection of the extension line and the horizontal line with the center of the circle of the front correction jig, set it as line segment g.

4. The calibration method of the wafer positioning system according to claim 3, characterized in that: In S32, the angle between line segment a and line segment b is calculated, including: The angle between the line connecting the positioning point of the edge of the correction jig and the center of the circle of the correction jig and the horizontal line is α, and α is an acute angle; When the target positioning point is located on the right side of the center of the circle of the calibration jig before movement, and the calibration jig is translated to the right, and when the target positioning point is located on the left side of the center of the circle of the calibration jig before movement, and the calibration jig is translated to the left, the angle ∠ab between the line segment a and the line segment b is 180°-α; When the target positioning point is located on the right side of the center of the circle of the correction jig before moving, and the correction jig is translated to the left, and when the target positioning point is located on the left side of the center of the circle of the correction jig before moving, and the correction jig is translated to the right, the angle ∠ab between line segment a and line segment b is α.

5. The calibration method of the wafer positioning system according to claim 4, characterized in that: The length of line segment c in S33 includes: The length of line segment a is the translation distance of the calibration fixture, and the length of line segment b is the radius r of the calibration fixture. The length of line segment c is calculated based on line segment a, line segment b and angle ∠ab in the triangle.

6. The calibration method of the wafer positioning system according to claim 5, characterized in that: Calculating the angle between line segment b and line segment c in S34 includes: Based on line segments a, b and c in the triangle, calculate the angle ∠bc between line segments b and c.

7. The calibration method of the wafer positioning system according to claim 6, characterized in that: Calculating the angle between line segment c and line segment d in S35 includes: The length of line segment d is the moving distance of the calibration fixture on the position detection device, and the length of line segment e is the radius r of the calibration fixture. According to line segments c, d and e in the triangle, the angle ∠cd between line segments c and d is calculated.

8. The calibration method of the wafer positioning system according to claim 7, characterized in that: Calculating the angle between the line segment f and the line segment g in S36 includes: When the target positioning point is located on the right side of the center of the calibration fixture before movement, the calibration fixture is translated to the right, and the line segment g is on the right side of the line segment f, ∠fg+∠bd=α, so the angle between the line segment f and the line segment g is ∠fg=α-∠bd=α-(∠bc+∠cd); When the target positioning point is located on the right side of the center of the calibration fixture before movement, the calibration fixture is translated to the right, and the line segment g is on the left side of the line segment f, ∠fg=α+∠bd, so the angle between the line segment f and the line segment g is ∠fg=α+(∠cd-∠bc); When the target positioning point is located on the right side of the center of the calibration fixture before movement, the calibration fixture is translated to the left, and line segment g is on the right side of line segment f, ∠fg+∠ac=∠cd, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle between line segment f and line segment g is ∠fg=α+∠cd+∠bc-180°; When the target positioning point is located on the right side of the center of the circle of the calibration fixture before movement, the calibration fixture is translated to the left, and the line segment g is on the left side of the line segment f, ∠fg+∠gc=∠cd, ∠gc=180°-∠ac, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle ∠fg between the line segment f and the line segment g=∠cd-∠bc-α; When the target positioning point is located at the lower left side of the center of the correction fixture before movement, the correction fixture is translated to the right, and the line segment g is on the left side of the line segment f, ∠fg+∠gc=∠cd, ∠gc=∠ac, ∠ac=180°-∠ab-∠bc, ∠ab=α, so the angle between the line segment f and the line segment g is ∠fg=α+∠cd+∠bc-180°; When the target positioning point is located on the upper left side of the center of the circle of the calibration fixture before movement, the calibration fixture is translated to the right, and the line segment g is on the left side of the line segment f, ∠fg = ∠cd-∠ac, ∠ac = 180°-∠ab-∠bc, ∠ab = α, so the angle between the line segment f and the line segment g is ∠fg = α + ∠cd + ∠bc-180°; When the target positioning point is located on the upper left side of the center of the circle of the calibration fixture before movement, the calibration fixture is translated to the left, and the line segment g is on the right side of the line segment f, ∠fg+∠bd=∠ab, ∠bd=∠cd-∠bc, so the angle between the line segment f and the line segment g is ∠fg=α+∠cd-∠bc; When the target positioning point is located on the upper left side of the center of the circle of the calibration fixture before movement, the calibration fixture is translated to the left, and the line segment g is on the left side of the line segment f, ∠fg+∠ab+∠bc+∠cd=180°, ∠ab=180°-α, so the angle between the line segment f and the line segment g is ∠fg=α-∠bc-∠cd; When the target positioning point is located on the lower right side of the center of the circle of the correction fixture before movement, the correction fixture translates to the right, and line segment g is on the right side of line segment f, ∠fg+∠ab+∠bc+∠cd=180°, ∠ab=180°-α, so the angle ∠fg between line segment f and line segment g=α-∠bc-∠cd.

9. The calibration method of the wafer positioning system according to claim 8, characterized in that: In S4, the actual coordinates of the center of the wafer are determined according to the inclination angle between the position detection device and the horizontal line, including: A coordinate system is established with the center of the calibration fixture before movement as the origin and the moving direction of the calibration fixture as the horizontal axis. The target positioning point on the edge of the calibration fixture after movement is set as A, and the coordinates of point A are (r*cosα+a, r*sinα); When in use, the intersection point between the wafer edge and the position detection device is set as B, and the distance L between A and B is obtained by multiplying the number of pixels by the pixel size, then the coordinates of point B are (r*cosα+a+L*cosθ, r*sinα+L*sinθ), and the actual coordinates of the center of the wafer are determined by calculating the coordinates of the four intersection points between the wafer edge and the four position detection devices; Wherein, θ is the angle ∠fg between line segment f and line segment g.

10. A calibration jig for a wafer positioning system, applied to the calibration method for a wafer positioning system according to claim 1, characterized in that: It includes a calibration jig of the same size as the wafer, and four positioning points arranged on the edge of the calibration jig, and the angle between the line connecting the positioning points on the edge of the calibration jig, the center of the calibration jig and the horizontal line is α; Among them, α is an acute angle, α∈[40°,70°].

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