Wafer calibrator reference point calibration method, device and equipment and storage medium
By controlling the rotation and movement of the wafer calibrator disk, and combining the transformation between polar and rectangular coordinate systems with least squares fitting, the reference point of the wafer calibrator is automatically determined, solving the problem of time-consuming manual calibration in the prior art and realizing efficient and convenient reference point calibration.
Patent Information
- Application Number
- CN202511027954.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-12-12
AI Technical Summary
In existing technologies, wafer calibrators require manual operation and specialized tooling equipment for reference point calibration, which is time-consuming and cannot be completed on-site.
By controlling the rotation and movement of the wafer calibrator's disk, and utilizing the offset between the wafer edge and the center point of the detection line of the correction sensor, the reference point is automatically determined. The automatic calibration of the reference point is achieved by using the conversion between polar coordinate system and rectangular coordinate system and the least squares method fitting.
It enables efficient and convenient calibration of wafer calibrator reference points without the aid of tooling and testing equipment, thus improving calibration efficiency and accuracy.
Smart Images
Figure CN121112976A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and in particular to a method, apparatus, device, and storage medium for calibrating reference points of a wafer calibrator. Background Technology
[0002] In semiconductor manufacturing, wafer calibrators play a crucial role in locating the wafer's center and notch, ensuring accurate wafer alignment. Before calibration, the calibrator's adsorption platform is moved to a reference point, rotated around this point, and the wafer offset corresponding to each rotation angle is recorded. This allows for the calculation of the wafer's center coordinates and notch position. Therefore, the accuracy of the reference point's position determines the precision of the wafer calibrator's center calculation.
[0003] A wafer calibrator with two directions of motion on a specific horizontal plane can calculate the wafer's center offset and notch position after one rotation. During the calibration process, the wafer calibrator typically requires manual operation using specialized tooling, high-precision reference plates, and measuring equipment for alignment. This involves adjusting the rotation axis, reference plate, and wafer inspection mechanism to the center position to find a suitable reference point, which is time-consuming and usually cannot be completed on-site. Summary of the Invention
[0004] This invention provides a wafer calibrator reference point calibration method, apparatus, equipment, and storage medium to solve the shortcomings of the prior art, which requires manual operation and the use of specialized tooling and testing equipment to align the wafer calibrator and find the reference point, which takes a long time and cannot be completed on-site, and realizes automatic calibration of the wafer calibrator.
[0005] This invention provides a method for calibrating reference points of a wafer calibrator, comprising the following steps: When the wafer is placed on the disk of the calibrator, the disk is rotated to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. Move the disk along the first direction to determine the second target point with the largest offset of the wafer; After moving the disk to the second target point, rotate it half a turn and move it along the first direction to determine the third target point with the largest offset of the wafer; The reference point of the disk is calibrated based on the second target point and the third target point.
[0006] According to the wafer calibrator reference point calibration method provided by the present invention, the calibration of the reference point of the disk based on the second target point and the third target point includes: The reference point of the disk is determined based on the second target point and the third target point; After moving the disk to the reference point, rotate it one full turn and calculate the center position of the wafer; Move the disk to the center position and obtain the first offset of the wafer; The reference point is calibrated based on the first offset.
[0007] According to the wafer calibrator reference point calibration method provided by the present invention, determining the reference point of the disk based on the second target point and the third target point includes: Based on the first coordinate value of the second target point in the first direction and the second coordinate value of the third target point in the first direction, calculate the third coordinate value of the reference point of the disk in the first direction; Based on the second offset corresponding to the second target point and the third offset corresponding to the third target point, the fourth coordinate value of the reference point in the second direction is calculated; the second direction is perpendicular to the first direction, and the plane containing the first direction and the second direction is perpendicular to the detection line of the correction sensor; the coordinate point corresponding to the third coordinate value and the fourth coordinate value is the reference point.
[0008] According to the wafer calibrator reference point calibration method provided by the present invention, the third coordinate value is the average of the first coordinate value and the second coordinate value; the fourth coordinate value is determined based on the average of the second offset and the third offset.
[0009] According to the wafer calibrator reference point calibration method provided by the present invention, the calibration of the reference point based on the first offset includes: The first offset is compared with a preset threshold range; If the first offset is not within the preset threshold range, return to and execute the step of rotating the disk to the first target point with the largest offset of the wafer to calibrate the reference point until the first offset is within the preset threshold range.
[0010] According to the wafer calibrator reference point calibration method provided by the present invention, the step of moving the disk to the reference point and rotating it one revolution, and calculating the center position of the wafer, includes: After moving the disk to the reference point, rotate it one full turn and collect the second offset of each sampling point on the edge of the wafer, as well as the rotation angle of the disk corresponding to the second offset; The polar coordinate radius corresponding to the disk is calculated based on the second offset. Based on the transformation relationship from polar coordinate system to rectangular coordinate system, the coordinates of each sampling point are transformed according to the polar coordinate radius and the rotation angle to obtain the target coordinate point of each sampling point in the rectangular coordinate system. The center position of the wafer is obtained by fitting the target coordinate points using the least squares method.
[0011] According to the wafer calibrator reference point calibration method provided by the present invention, rotating the disk to the first target point with the largest offset of the wafer includes: The disk is driven to rotate, and during the rotation of the disk, the trend of the offset of the wafer is obtained; the trend of the offset is either gradually increasing or gradually decreasing. Determine the critical point at which the trend of change abruptly changes; the critical point is the first target point where the offset of the wafer is the largest; the abrupt change in the trend of change includes changing from gradually increasing to gradually decreasing, and changing from gradually decreasing to gradually increasing. Rotate the disk to the critical point.
[0012] The present invention also provides a wafer calibrator reference point calibration device, comprising the following modules: The first driving module is used to rotate the disk to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system, when the wafer is placed on the disk of the calibrator; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. The second driving module is used to move the disk along the first direction and determine the second target point with the largest offset of the wafer; The third driving module is used to move the disk to the second target point, rotate it half a revolution, and move it along the first direction to determine the third target point with the largest offset of the wafer. The calibration module is used to calibrate the reference point of the disk based on the second target point and the third target point.
[0013] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the wafer calibrator reference point calibration method as described above.
[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the wafer calibrator reference point calibration method as described above.
[0015] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the wafer calibrator reference point calibration method as described above.
[0016] The wafer calibrator reference point calibration method, apparatus, equipment, and storage medium provided by this invention obtain the position point of the disk with the largest wafer offset by controlling the rotation and movement of the disk, and calibrate the reference point of the disk. By utilizing the mutual cancellation of positive and negative offsets on both sides of the center point of the detection line of the wafer, the calibration of the reference point is achieved. Thus, automatic calibration of the wafer calibrator reference point is achieved without the aid of tooling and testing equipment, which is time-saving, efficient, and convenient for on-site calibration of the wafer calibrator reference point. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 This is a schematic flowchart of the wafer calibrator reference point calibration method provided by the present invention.
[0019] Figure 2 This is a schematic diagram of the principle of the correction sensor provided by the present invention.
[0020] Figure 3 This is a schematic diagram of the location of the first target point provided by the present invention.
[0021] Figure 4 This is a schematic diagram showing the location of the second target point provided by the present invention.
[0022] Figure 5 This is a schematic diagram of the reference point calibration process for the wafer calibrator provided by the present invention.
[0023] Figure 6 This is a schematic diagram of the wafer calibrator reference point calibration device provided by the present invention.
[0024] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0026] This invention provides a wafer calibrator reference point calibration method for calibrating the reference points of a wafer calibrator. It can automatically calibrate the reference points of a wafer calibrator without using high-precision tooling or testing equipment, relying solely on the calibrator's own configuration.
[0027] Specifically, Figure 1 This is a schematic flowchart of the wafer calibrator reference point calibration method provided by the present invention, as shown below. Figure 1 As shown, the method includes the following steps: Step 100: When the wafer is placed on the disk of the calibrator, the disk is rotated to the first target point with the largest offset of the wafer, taking the current position of the disk as the origin of the coordinate system; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. Step 200: Move the disk along the first direction to determine the second target point with the largest offset of the wafer; Step 300: After moving the disk to the second target point, rotate it half a revolution and move it along the first direction to determine the third target point with the largest offset of the wafer; Step 400: Based on the second target point and the third target point, calibrate the reference point of the disk.
[0028] In semiconductor manufacturing, wafer calibrators are used to calibrate the position and orientation of wafers, thereby reducing process deviations and improving the quality and performance of semiconductor products. The calibrator's reference point serves as a reference for detecting the wafer's position and orientation; it is the reference point in the wafer calibration process.
[0029] Before calibrating a wafer, a reference point must first be determined. This invention can automatically calibrate the reference point of the calibrator without using high-precision tooling and testing equipment. It is efficient, time-saving, and convenient, and can be completed on-site.
[0030] Specifically, first, the wafer is placed on a disk in the calibrator. With the wafer on the disk, the disk is rotated to the first target point where the wafer's offset is greatest, using the disk's current position as the origin. The wafer's offset is detected by a wafer inspection mechanism on the calibrator, which can be called a spin correction sensor, and can be a laser beam sensor.
[0031] The wafer offset is the distance between the edge of the wafer and the center point of the detection line of the calibration sensor, as referenced. Figure 2 The schematic diagram of the alignment sensor shows that its laser emitter emits a laser beam perpendicular to the plane of the wafer as a detection signal. This laser beam, called the detection line, appears as a line segment when viewed from above. The portion of the wafer located between the laser emitter and receiver of the alignment sensor blocks the laser beam emitted by the emitter, preventing the receiver from receiving the blocked portion. The position of the wafer edge is determined based on the length of the blocked laser beam in the direction perpendicular to its transmission direction, i.e., the length of the unreceived laser beam. The distance between this position and the center point of the detection line is the offset of the wafer edge. If the wafer edge is located at the center point of the detection line, the offset is 0, meaning there is no offset.
[0032] Furthermore, the wafer calibrator has two directions of motion on a plane parallel to the plane where the wafer is located, namely the first direction and the second direction. The laser beam emitted by the laser emitter of the correction sensor is perpendicular to the wafer and also perpendicular to the plane where the first and second directions are located. The first direction is perpendicular to the second direction.
[0033] The first target point is the point where the center of the wafer and the center of the disk are collinear, such as... Figure 3 As shown, during the disk rotation process, the intersection of the line connecting the center of the wafer and the center of the disk with the edge of the wafer is the first target point with the largest wafer edge offset, which is the position where the disk is rotated to coincide with the first target point and the detection line.
[0034] Then, the disk is moved along the first direction to determine the second target point with the largest offset of the wafer, such as... Figure 4 As shown, during the movement of the wafer along the first direction, when the detection line of the correction sensor coincides with the wafer diameter, a second target point with an offset greater than the first target point is located on the edge of the wafer. The first direction is perpendicular to the detection line from a top-down view, while the second direction is parallel to the detection line from a top-down view.
[0035] After moving the disk to the second target point, it is rotated half a revolution, and then moved along the first direction to determine the third target point with the largest wafer offset. It can be understood that the distance between the wafer edge and the center point of the detection line includes both cases where the wafer edge exceeds the center point of the detection line in the second direction and cases where the wafer edge does not exceed the center point of the detection line in the second direction. When the wafer edge exceeds the center point of the detection line in the second direction, the wafer obstructs more than half of the laser beam; when the wafer edge exceeds the center point of the detection line in the second direction, the wafer obstructs less than half of the laser beam. In this embodiment, when the wafer edge is located at the center point of the detection line, the offset is defined as 0. When the wafer edge obstructs less than half of the laser beam, the offset of the wafer edge is defined as negative. When the wafer edge obstructs more than half of the laser beam, the offset of the wafer edge is defined as positive.
[0036] Therefore, if the offset of the wafer at the first and second target points is positive, then after the disk rotates half a revolution, the offset corresponding to the third target point with the largest wafer offset will be negative. If the offsets corresponding to the first and second target points are negative, then after the disk rotates half a revolution, the offset corresponding to the third target point with the largest wafer offset will be positive.
[0037] Optionally, when determining the third target point, the direction of movement of the disk along the first direction can be opposite to the direction of movement of the disk along the first direction when determining the second target point.
[0038] The reference point of the disk is calibrated based on the second and third target points. Optionally, the reference point of the disk is calibrated based on the wafer offset of the disk at the second target point and the wafer offset of the disk at the third target point.
[0039] In one embodiment, the wafer offset corresponding to the second target point is a positive offset, and the wafer offset corresponding to the third target point is a negative offset; alternatively, the wafer offset corresponding to the second target point is a negative offset, and the wafer offset corresponding to the third target point is a positive offset. The reference point of the disk is located between the first target point and the second target point, thereby calibrating the reference point of the disk based on the second target point and the third target point.
[0040] In this embodiment, by controlling the rotation and movement of the disk, the position of the disk with the largest wafer offset is obtained, and the reference point of the disk is calibrated. The mutual cancellation of the positive and negative offsets of the wafer is used to achieve the calibration of the reference point. Thus, the automatic calibration of the wafer calibrator reference point can be achieved without the aid of tooling and testing equipment, which is time-saving, efficient and convenient for on-site calibration of the wafer calibrator reference point.
[0041] Optionally, when rotating the disk to the first target point with the largest wafer offset, this is specifically achieved by monitoring the trend of the offset change. Step 100, rotating the disk to the first target point with the largest wafer offset, may further include: Step 101: Drive the disk to rotate, and during the rotation of the disk, obtain the trend of the offset of the wafer; the trend is either gradually increasing or gradually decreasing. Step 102: Determine the critical point at which the trend of change changes abruptly; the critical point is the first target point where the offset of the wafer is the largest; the abrupt change in the trend of change includes changing from gradually increasing to gradually decreasing, and changing from gradually decreasing to gradually increasing. Step 103: Rotate the disk to the critical point.
[0042] The disk is driven to rotate, and during the rotation of the disk, the trend of the wafer offset is obtained. The trend of the offset is gradually increasing or gradually decreasing. The critical point at which the trend of the offset changes abruptly is determined. This critical point is the first target point where the wafer offset is the largest. The trend of the offset changes abruptly includes changing from gradually increasing to gradually decreasing, and changing from gradually decreasing to gradually increasing.
[0043] Optionally, if the offset of the first target point is positive, the wafer's offset tends to increase gradually before the disk rotates to the first target point, and the first target point is the critical point where the wafer's offset tends to decrease from increasing to decreasing. If the offset of the first target point is negative, the wafer's offset tends to decrease gradually before the disk rotates to the first target point, and the first target point is the critical point where the wafer's offset tends to increase from decreasing to increasing.
[0044] The disk is rotated to the first target point with the largest offset from the wafer. Specifically, the disk is driven to rotate, and the offset of the wafer edge is monitored during the rotation to determine the trend of the offset. When the trend of the offset changes abruptly, the critical point where the change occurs is the first target point. The disk is then rotated to this first target point.
[0045] Optionally, the calibration of the disk's reference point involves determining the disk's reference point based on the second and third target points, then rotating the disk to calculate the wafer's center position, and further calibrating the disk's reference point based on the wafer's center position.
[0046] Step 400 may also include: Step 410: Determine the reference point of the disk based on the second target point and the third target point; Step 420: Move the disk to the reference point and rotate it one revolution, then calculate the center position of the wafer; Step 430: Move the disk to the center position and obtain the first offset of the wafer; Step 440: Calibrate the reference point based on the first offset.
[0047] Specifically, a reference point for the disk is determined based on the second and third target points. Optionally, the reference point of the disk is located between the second and third target points. In one embodiment, the second and third target points are weighted according to their corresponding offsets, and the calculated coordinates are used as the reference point of the disk.
[0048] The disk is moved to the reference point and then rotated one full circle to calculate the center position of the wafer. The disk is then moved to the calculated center position to obtain the first offset of the wafer at that position. Based on the calculated first offset, the reference point is further calibrated.
[0049] Optionally, the coordinates of the reference point are calculated from the coordinates and offset of the second target point and the coordinates and offset of the third target point. Step 410 may also include: Step 411: Calculate the third coordinate value of the reference point of the disk in the first direction based on the first coordinate value of the second target point in the first direction and the second coordinate value of the third target point in the first direction; Step 412: Based on the second offset corresponding to the second target point and the third offset corresponding to the third target point, calculate the fourth coordinate value of the reference point in the second direction; the second direction is perpendicular to the first direction, and the plane containing the first direction and the second direction is perpendicular to the detection line of the correction sensor; the coordinate point corresponding to the third coordinate value and the fourth coordinate value is the reference point.
[0050] Based on the first coordinate value of the second target point in the first direction and the second coordinate value of the third target point in the first direction, calculate the third coordinate value of the reference point of the disk in the first direction.
[0051] Furthermore, based on the second offset corresponding to the second target point and the third offset corresponding to the third target point, the fourth coordinate value of the reference point in the second direction is calculated. Based on the third coordinate value in the first direction and the fourth coordinate value in the second direction, a coordinate point can be uniquely determined, which is the reference point.
[0052] Optionally, step 420 may also include: Step 421: After moving the disk to the reference point, rotate it one full turn and collect the second offset of each sampling point on the edge of the wafer, as well as the rotation angle of the disk corresponding to the second offset; Step 422: Calculate the polar coordinate radius corresponding to the disk based on the second offset, and perform coordinate transformation on each sampling point according to the polar coordinate radius and the rotation angle based on the transformation relationship from polar coordinate system to rectangular coordinate system to obtain the target coordinate point of each sampling point in the rectangular coordinate system; Step 423: The least squares method is used to fit each of the target coordinate points to obtain the center position of the wafer.
[0053] After the disk is moved to the reference point, it rotates one revolution. The wafer placed on the disk rotates with the disk. During the disk's rotation, the second offset of each sampling point on the wafer edge and the corresponding rotation angle of the disk are collected. The polar coordinate radius of the disk is calculated based on the second offset. Then, based on the calculated polar coordinate radius and the transformation relationship between the polar coordinate system and the rectangular coordinate system, the coordinates of each sampling point are transformed according to the correspondence between the offset and the rotation angle, thus obtaining the target coordinates of each sampling point in the rectangular coordinate system.
[0054] Furthermore, the least squares method is used to fit the target coordinates of each sampling point to obtain the center region of the circle fitted by each sampling point, and the center of the circle region is determined as the center position of the wafer.
[0055] For the coordinate transformation between polar coordinates and rectangular coordinates, the polar coordinates are used to represent each sampling point as (R, θ), where R is the polar coordinate radius determined by the offset of the sampling point, also known as the offset value, and θ is the rotation angle of the corresponding disk. In the rectangular coordinates, each sampling point is represented as (x, y). The transformation relationship between the polar coordinates and the rectangular coordinates can be represented as: x = Rcos(θ), y = Rsin(θ).
[0056] In one embodiment, the offset value of each sampling point on the edge of the wafer is added to a fixed value, such as 150mm, which is the radius of the polar coordinate system. Then, based on the rotation angle corresponding to the offset, the target coordinate point of the sampling point in the rectangular coordinate system is calculated.
[0057] A least-squares fit is performed on each target coordinate point to obtain a circle. The goal of the least-squares fit is to minimize the squared error. Once the error converges to its minimum value, the coordinates of the circle's center are obtained, which represents the center position of the wafer. The error is calculated by subtracting the square of the fitted radius from the square of the distance between each target point's coordinate and the fitted circle's center coordinate.
[0058] Furthermore, for the coordinate values of the reference point, the coordinate value in the first direction is the average of the first coordinate value corresponding to the second target point and the second coordinate value corresponding to the third target point, while the coordinate value in the second direction is determined based on the average of the second offset corresponding to the second target point and the third offset corresponding to the third target point.
[0059] Optionally, based on a first offset at the wafer's center position, the reference point is further calibrated, specifically by comparing the first offset with a preset threshold range. Therefore, step 440 may further include: Step 441: Compare the first offset with a preset threshold range; Step 442: If the first offset is not within the preset threshold range, return to and execute the step of rotating the disk to the first target point with the largest offset of the wafer to calibrate the reference point until the first offset is within the preset threshold range.
[0060] The first offset of the wafer at the center position is compared with a preset threshold range. If the first offset is no longer within the preset threshold range, the step of moving the disk boat to the first target point with the largest offset of the wafer is repeated until the calculated first offset is within the preset threshold range.
[0061] In one embodiment, refer to Figure 5 The calibration process for the calibrator reference point shown is as follows: First, place the wafer on the calibrator disk and establish a rectangular coordinate system with the current position of the disk as the origin. This rectangular coordinate system includes a first direction and a second direction, where the first direction is denoted as the x-axis and the second direction as the y-axis.
[0062] Drive the disk to rotate to the first target point A with the largest offset of the wafer. Then control the disk to move along the first direction. During the movement, determine the second target point B with the largest wafer offset and record the coordinate value x1 of point B in the first direction and its corresponding offset y1. Move the disk to point B, then rotate it half a circle (180 degrees), and then move the disk along the first direction to obtain the third target point C with the largest wafer offset during the movement. Record the coordinate value x2 of point C in the first direction and its corresponding offset y2.
[0063] Further, based on the coordinates of points B and C and their corresponding offsets, the coordinates of the reference point (x0, y0) are calculated, where x0 = 0.5 × (x1 + x2) and y0 = -0.5 × (y1 + y2). The disk is then moved to the reference point (x0, y0), and rotated one full circle. An alignment algorithm is used to calculate the center position of the wafer. The disk is then moved to the center position, and the wafer offset δy is recorded. Specifically, the alignment algorithm calculates the wafer center position by rotating the wafer one full circle, collecting the offset values and corresponding rotation angles of each sampling point on the wafer edge, adding 150mm to the offset value to obtain the R value in polar coordinates, converting the polar coordinates of the sampling points to rectangular coordinates based on the rotation angle, and performing least-squares fitting on the rectangular coordinates to obtain the center coordinates.
[0064] Finally, when the disk is at the center of the wafer, the wafer offset δy is compared with a preset threshold range. If the offset δy is within the preset threshold range, the calculated reference point (x0, y0) is the calibrated reference point. Otherwise, the step of rotating the disk to the first target point A with the largest wafer offset is repeated, and the reference point is recalculated until the calculated offset δy is within the preset threshold range, thus completing the calibration of the wafer calibrator's reference point.
[0065] It is understandable that the calculation accuracy of the first target point, the second target point, the third target point, and the center position of the wafer is positively correlated with the frequency of the laser beam emitted by the polarization correction sensor.
[0066] In this embodiment, the reference point is calibrated using the point with the largest positive and negative offset. By utilizing the disk position corresponding to the largest offset, the position of the reference point can be accurately determined, enabling rapid calibration of the reference point and improving the calibration efficiency of the calibrator's reference point, making it convenient and efficient.
[0067] Furthermore, after calculating the reference point based on the position with the largest offset, the alignment algorithm is used to calculate the center position of the wafer and obtain the offset of the wafer at the center position of the disk. The offset is compared with a preset threshold range to determine whether the accuracy of the reference point meets the requirements, thus ensuring the calibration accuracy of the reference point.
[0068] The wafer calibrator reference point calibration device provided by the present invention is described below. The wafer calibrator reference point calibration device described below can be referred to in correspondence with the wafer calibrator reference point calibration method described above.
[0069] Reference Figure 6 The wafer calibrator reference point calibration device provided in this embodiment of the invention includes: The first driving module 10 is used to rotate the disk to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system, when the wafer is placed on the disk of the calibrator; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. The second driving module 20 is used to move the disk along the first direction and determine the second target point with the largest offset of the wafer; The third driving module 30 is used to move the disk to the second target point, rotate it half a revolution, and move it along the first direction to determine the third target point with the largest offset of the wafer. The calibration module 40 is used to calibrate the reference point of the disk based on the second target point and the third target point.
[0070] In one embodiment, the calibration module 40 is further configured to: The reference point of the disk is determined based on the second target point and the third target point; After moving the disk to the reference point, rotate it one full turn and calculate the center position of the wafer; Move the disk to the center position and obtain the first offset of the wafer; The reference point is calibrated based on the first offset.
[0071] In one embodiment, the calibration module 40 is further configured to: Based on the first coordinate value of the second target point in the first direction and the second coordinate value of the third target point in the first direction, calculate the third coordinate value of the reference point of the disk in the first direction; Based on the second offset corresponding to the second target point and the third offset corresponding to the third target point, the fourth coordinate value of the reference point in the second direction is calculated; the second direction is perpendicular to the first direction, and the plane containing the first direction and the second direction is perpendicular to the detection line of the correction sensor; the coordinate point corresponding to the third coordinate value and the fourth coordinate value is the reference point.
[0072] In one embodiment, the third coordinate value is the average of the first coordinate value and the second coordinate value; the fourth coordinate value is determined based on the average of the second offset and the third offset.
[0073] In one embodiment, the calibration module 40 is further configured to: The first offset is compared with a preset threshold range; If the first offset is not within the preset threshold range, return to and execute the step of rotating the disk to the first target point with the largest offset of the wafer to calibrate the reference point until the first offset is within the preset threshold range.
[0074] In one embodiment, the calibration module 40 is further configured to: After moving the disk to the reference point, rotate it one full turn and collect the second offset of each sampling point on the edge of the wafer, as well as the rotation angle of the disk corresponding to the second offset; The polar coordinate radius corresponding to the disk is calculated based on the second offset. Based on the transformation relationship from polar coordinate system to rectangular coordinate system, the coordinates of each sampling point are transformed according to the polar coordinate radius and the rotation angle to obtain the target coordinate point of each sampling point in the rectangular coordinate system. The center position of the wafer is obtained by fitting the target coordinate points using the least squares method.
[0075] In one embodiment, the first driving module 10 is further configured to: The disk is driven to rotate, and during the rotation of the disk, the trend of the offset of the wafer is obtained; the trend of the offset is either gradually increasing or gradually decreasing. Determine the critical point at which the trend of change abruptly changes; the critical point is the first target point where the offset of the wafer is the largest; the abrupt change in the trend of change includes changing from gradually increasing to gradually decreasing, and changing from gradually decreasing to gradually increasing. Rotate the disk to the critical point.
[0076] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device may include: a processor 710, a communications interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communications interface 720, and the memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute the steps of the wafer calibrator reference point calibration method, such as including: When the wafer is placed on the disk of the calibrator, the disk is rotated to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. Move the disk along the first direction to determine the second target point with the largest offset of the wafer; After moving the disk to the second target point, rotate it half a turn and move it along the first direction to determine the third target point with the largest offset of the wafer; The reference point of the disk is calibrated based on the second target point and the third target point.
[0077] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0078] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is capable of performing the steps of the wafer calibrator reference point calibration method provided by the above methods, for example including: When the wafer is placed on the disk of the calibrator, the disk is rotated to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. Move the disk along the first direction to determine the second target point with the largest offset of the wafer; After moving the disk to the second target point, rotate it half a turn and move it along the first direction to determine the third target point with the largest offset of the wafer; The reference point of the disk is calibrated based on the second target point and the third target point.
[0079] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the wafer calibrator reference point calibration method provided by the methods described above, including, for example: When the wafer is placed on the disk of the calibrator, the disk is rotated to the first target point with the largest offset of the wafer, with the current position of the disk as the origin of the coordinate system; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. Move the disk along the first direction to determine the second target point with the largest offset of the wafer; After moving the disk to the second target point, rotate it half a turn and move it along the first direction to determine the third target point with the largest offset of the wafer; The reference point of the disk is calibrated based on the second target point and the third target point.
[0080] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0081] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.
[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A wafer calibrator reference point calibration method, characterized by, The method comprises the following steps: when the wafer is placed on the disc of the calibrator, taking the current position of the disc as the coordinate origin, rotating the disc to a first target point with the largest offset of the wafer; the offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator; moving the disc in a first direction to determine a second target point with the largest offset of the wafer; after moving the disc to the second target point, rotating the disc by half a circle, moving the disc in the first direction to determine a third target point with the largest offset of the wafer; based on the second target point and the third target point, calibrating the reference point of the disc.
2. The wafer calibrator reference point calibration method of claim 1, wherein, The calibration of the reference point of the disc based on the second target point and the third target point comprises: determining the reference point of the disc according to the second target point and the third target point; rotating the disc by a full circle after moving the disc to the reference point, and calculating the center position of the wafer; moving the disc to the center position of the wafer and obtaining a first offset of the wafer; calibrating the reference point based on the first offset.
3. The wafer calibrator reference point calibration method of claim 2, wherein, The determination of the reference point of the disc according to the second target point and the third target point comprises: calculating a third coordinate value of the reference point of the disc in the first direction according to a first coordinate value of the second target point in the first direction and a second coordinate value of the third target point in the first direction; calculating a fourth coordinate value of the reference point in a second direction based on a second offset corresponding to the second target point and a third offset corresponding to the third target point; the second direction is perpendicular to the first direction, and the plane where the first direction and the second direction are located is perpendicular to the detection line of the correction sensor; the coordinate point corresponding to the third coordinate value and the fourth coordinate value is the reference point.
4. The wafer calibrator reference point calibration method of claim 3, wherein, The third coordinate value is the average of the first coordinate value and the second coordinate value; the fourth coordinate value is determined according to the average of the second offset and the third offset.
5. The wafer calibrator reference point calibration method of claim 2, wherein, The calibration of the reference point based on the first offset comprises: comparing the first offset with a preset threshold range; if the first offset is not within the preset threshold range, returning to execute the step of rotating the disc to the first target point with the largest offset of the wafer to calibrate the reference point until the first offset is within the preset threshold range.
6. The wafer calibrator reference point calibration method of claim 2, wherein, The rotating of the disc by a full circle after moving the disc to the reference point and the calculation of the center position of the wafer comprise: rotating the disc by a full circle after moving the disc to the reference point, collecting the second offset of each sampling point of the edge of the wafer and the rotation angle of the disc corresponding to the second offset; calculating the polar coordinate radius corresponding to the disc based on the second offset, and performing coordinate conversion on each sampling point according to the polar coordinate radius and the rotation angle based on the conversion relationship from the polar coordinate system to the rectangular coordinate system to obtain the target coordinate point of each sampling point in the rectangular coordinate system; The least square method is used to fit each target coordinate point to obtain the center position of the wafer.
7. The wafer calibrator reference point calibration method of claim 1, wherein, The first target point with the maximum offset of the wafer is obtained by rotating the disc. The disc is driven to rotate, and a change trend of the offset of the wafer is obtained during the rotation of the disc; the change trend is gradually increasing or gradually decreasing. A critical point is determined, at which the change trend jumps; the critical point is the first target point with the maximum offset of the wafer; the change trend jumping includes changing from gradually increasing to gradually decreasing, and changing from gradually decreasing to gradually increasing. The disc is rotated to the critical point.
8. A wafer calibrator reference point calibration apparatus, characterized by, The method comprises the following steps: A first driving module is configured to rotate the disc to a first target point with the maximum offset of the wafer, with the current position of the disc as the coordinate origin when the wafer is placed on the disc of the calibrator. The offset is the distance between the edge of the wafer and the center point of the detection line of the correction sensor of the calibrator. A second driving module is configured to move the disc along a first direction to determine a second target point with the maximum offset of the wafer. A third driving module is configured to rotate the disc by half a circle after moving the disc to the second target point, move the disc along the first direction, and determine a third target point with the maximum offset of the wafer. A calibration module is configured to calibrate the reference point of the disc based on the second target point and the third target point.
9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the wafer calibrator reference point calibration method according to any one of claims 1 to 7. 10.A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the wafer calibrator reference point calibration method according to any one of claims 1 to 7.