Wafer calibration method, main controller, electronic equipment and storage medium
By acquiring and analyzing the sampled data during wafer rotation, positioning the wafer notch and center position, and using the drive motor for accurate calibration, the problem of low calibration accuracy of the robot is solved, and high-precision and automated wafer calibration are achieved.
Patent Information
- Application Number
- CN202411801058.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, the accuracy of wafer calibration is not high when robots are used to achieve wafer calibration, and the calibration error is caused by wear, vibration and elastic deformation of the mechanical system.
By acquiring the plurality of first sampling data when the wafer is rotated for one round, the second sampling data of the wafer notch is determined, the wafer notch position and the center position are positioned, and precise position calibration is performed using the driving motor to avoid the influence of mechanical errors.
Achieve higher accuracy and stable wafer calibration, reduces the number of beats required for calibration, improves productivity, and requires no manual intervention or manual adjustment, achieving a higher degree of automation.
Smart Images
Figure CN119993889A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer calibration method, a main controller, an electronic device and a storage medium. Background Art
[0002] With the development of industrial technology, the requirements for efficient and accurate semiconductor equipment manufacturing are getting higher and higher. Wafers are the basic materials for semiconductor equipment manufacturing. They are usually supported by silicon and are highly purified and processed to form tiny circuit structures. Wafer calibration is an indispensable part of semiconductor equipment manufacturing, which is directly related to the performance and reliability of the product.
[0003] The existing technology usually uses a robot to move the wafer from one process position to another, and places the wafer at the specified position of the process equipment through continuous adjustment. However, the robot calibration depends on the accuracy and stability of the mechanical device. Due to the wear, vibration and elastic deformation of the mechanical system, there will be a certain error in the wafer calibration. Summary of the invention
[0004] The present invention provides a wafer calibration method, a main controller, an electronic device and a storage medium, which are used to solve the problem of low accuracy when wafer calibration is achieved by a robot in the prior art.
[0005] In a first aspect, the present invention provides a wafer calibration method, comprising: Acquire a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; Based on the plurality of first sampling data, determining second sampling data of the wafer notch; Determine the wafer center position and the wafer notch position according to the second sampling data; According to the wafer notch position and the wafer center position, a driving motor is controlled to perform position calibration on the wafer.
[0006] In one embodiment, determining the second sampling data of the wafer notch based on the plurality of first sampling data includes: Performing derivative calculation on each first sampling data to obtain multiple derivative values; determining outliers among the plurality of derivative values; The first sampling data used to calculate the outlier value is determined as the second sampling data of the wafer notch.
[0007] In one embodiment, the wafer is driven to rotate by a vacuum chuck; any of the first sampling data includes the length and angle of the sampling point relative to the center of the vacuum chuck; the derivative calculation of each first sampling data is calculated by the following formula: ; Where n represents the nth sampling point; g(n) represents the derivative value corresponding to the nth sampling point; l (n) represents the length corresponding to the nth sampling point; l (n-1) represents the length corresponding to the n-1th sampling point; a(n) represents the angle corresponding to the n-1th sampling point; a(n-1) represents the angle corresponding to the n-1th sampling point.
[0008] In one embodiment, determining the center position of the wafer according to the second sampling data includes: Eliminate the second sampling data from the plurality of first sampling data to obtain remaining sampling data; Convert the remaining sampled data into first rectangular coordinates in a first rectangular coordinate system; the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum chuck as the origin; According to the first rectangular coordinate, a circle is fitted; The center of the circle is determined as the center of the wafer, and the coordinates of the center are determined as the position of the center of the wafer.
[0009] In one embodiment, determining the wafer notch position according to the second sampling data includes: converting the second sampling data into second rectangular coordinates in the first rectangular coordinate system; Subtract the coordinate of the center of the circle from the second rectangular coordinate to obtain a third rectangular coordinate of the second sampling data in a second rectangular coordinate system; the second rectangular coordinate system is a rectangular coordinate system with the center of the wafer as the origin; Convert the third rectangular coordinates into polar coordinates to obtain corrected second sampling data; According to the corrected second sampling data, a quadratic curve is obtained by fitting; Determine the minimum point of the quadratic curve as the lowest point of the wafer notch; The wafer notch position is determined according to the angle of the lowest point of the wafer notch relative to the center of the wafer.
[0010] In one embodiment, controlling a driving motor to calibrate the position of the wafer according to the wafer notch position and the wafer center position includes: According to the wafer notch position and the angle compensation value, controlling the driving motor to rotate the wafer notch to a preset angle; According to the center position of the wafer, the driving motor is controlled to move the center of the wafer to a preset position.
[0011] In one embodiment, the angle compensation value is determined by: Constructing a triangle according to the center position of the wafer, the coordinates of the lowest point and the center position of the vacuum chuck; According to the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated to obtain an angle compensation value.
[0012] In a second aspect, the present invention further provides a main controller, comprising: An acquisition module, used for acquiring a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; A wafer notch data determination module, configured to determine second sampling data of the wafer notch based on the plurality of first sampling data; A position determination module, used for determining the center position of the wafer and the wafer notch position according to the second sampling data; The control calibration module is used to control the driving motor to perform position calibration on the wafer according to the wafer notch position and the wafer center position.
[0013] In a third aspect, the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any of the wafer calibration methods described above are implemented.
[0014] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the wafer calibration methods described above are implemented.
[0015] The wafer calibration method, main controller, electronic device and storage medium provided by the present invention, since the wafer notch is located at the edge of the wafer, second sampling data belonging to the wafer notch can be screened out from the first sampling data of the wafer edge obtained, and the wafer notch position and the wafer center position are located by the second sampling data at the wafer notch. On the basis of the known wafer notch position and the wafer center position, the wafer is accurately calibrated by driving a motor, which can effectively avoid the influence of the mechanical error of the manipulator on the positioning accuracy, and does not require human intervention or manual adjustment, thereby achieving a higher degree of automation, and can provide a more accurate and stable wafer calibration effect, while reducing the number of beats required for wafer calibration, and does not need to adjust the position of the wafer multiple times, thereby effectively improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the present invention or 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 It is a flow chart of the wafer calibration method provided by the present invention.
[0018] Figure 2 It is a schematic diagram of the wafer aligner device provided by the present invention.
[0019] Figure 3 It is a control logic flow chart provided by the present invention.
[0020] Figure 4 It is a schematic diagram of the data collection process provided by the present invention.
[0021] Figure 5 It is a schematic diagram of the process of determining the center position of a wafer provided by the present invention.
[0022] Figure 6 It is a schematic diagram of the process of determining the wafer notch position provided by the present invention.
[0023] Figure 7 This is the image before the gap sampling data correction provided by the present invention.
[0024] Figure 8 This is the image after the gap sampling data provided by the present invention is corrected.
[0025] Fig. 9 This is one of the schematic diagrams of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention.
[0026] Fig.10 This is the second schematic diagram of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention.
[0027] Fig.11 This is the third schematic diagram of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention.
[0028] Fig.12 It is a structural schematic diagram of the main controller provided by the present invention.
[0029] Fig.13 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION
[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0031] The terms "first", "second", etc. in the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein.
[0032] Combine the following Figure 1-Figure 13 The present invention describes a wafer calibration method, a main controller, an electronic device and a storage medium.
[0033] Combination Figure 1 , Figure 1 It is a flow chart of the wafer calibration method provided by the present invention.
[0034] like Figure 1 As shown, the method includes the following: Step 101, obtaining a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; Step 102: determining second sampling data of the wafer notch based on the plurality of first sampling data; Step 103: Determine the wafer center position and the wafer notch position according to the second sampling data; Step 104 : controlling a driving motor to calibrate the position of the wafer according to the wafer notch position and the wafer center position.
[0035] It should be noted that the wafer calibration method provided in the embodiment of the present invention is implemented based on a wafer calibration device. Figure 2 As shown, Figure 2 Schematic diagram of the wafer aligner device provided by the present invention. Figure 2It can be seen that the wafer calibration device mainly includes a main controller, a laser sensor, a vacuum suction cup, and X, Y, and T-axis motors. Among them, the vacuum suction cup is used to fix the wafer after placing it on it so as to drive the wafer to rotate; the laser sensor is used to drive the wafer to rotate one circle and continuously detect the edge of the wafer during rotation; among the X, Y, and T-axis motors, the X-axis motor is usually responsible for moving along the left and right directions (or front and back directions, depending on the coordinate system definition) on the horizontal plane, the Y-axis motor is usually responsible for moving along the front and back directions (or left and right directions, depending on the coordinate system definition) on the horizontal plane, and the T-axis motor is usually responsible for the rotation of the vacuum suction cup, while driving the wafer to rotate, and can adjust the angle of the wafer; the main controller is used to collect data detected by the laser sensor at a regular interval, and after stopping data collection, it processes the collected data, analyzes the wafer notch position and the wafer center position, and finally drives the X, Y, and T-axis motors to rotate the wafer notch to the angle specified by the host computer and move the wafer center to the position specified by the host computer. The control logic steps can be referred to Figure 3 , Figure 3 It is a control logic flow chart provided by the present invention.
[0036] Since the wafer calibration method provided by the present invention mainly processes the collected edge sampling data, analyzes the wafer notch position and the wafer center position, and then controls the drive motor to calibrate the wafer according to the wafer notch position and the wafer center position, that is, the wafer calibration method provided by the present invention is mainly implemented by the main controller. Therefore, the embodiment of the present invention takes the main controller in the wafer calibration device as the execution subject as an example to describe the wafer calibration method.
[0037] Specifically, the wafer calibration device is initialized before operation, otherwise it is not allowed to work, which can prevent the data stored in the last operation from affecting the current operation.
[0038] After initialization, when starting work, place the wafer on the vacuum chuck, and the wafer calibration device opens the vacuum valve to suck the wafer. Then the vacuum chuck drives the wafer to rotate for one circle. During the rotation, the laser sensor continuously detects the edge of the wafer. The laser sensor can be a linear array laser sensor or other similar products. As long as the final output result is the value of detecting the edge of the wafer, this method can be used to calibrate the position of the wafer.
[0039] During the process of the laser sensor detecting the edge of the wafer, the main controller regularly collects and saves the data detected by the laser sensor, so the main controller can sample thousands or even tens of thousands of points according to the automatic calibration cycle time set by the user.
[0040] Combination Figure 4 , Figure 4It is a schematic diagram of the data acquisition process provided by the present invention. Specifically, after the calibration process starts, the T-axis motor starts to rotate. After the T-axis motor moves at a uniform speed, the main controller turns on the timer and collects the laser sensor and T-axis encoder data according to the timer. In the wafer calibration device, there is a two-dimensional coordinate axis by default, and the origin of the two-dimensional coordinate axis is always considered to be the center of the suction cup. Therefore, the edge data collected by the laser sensor is the distance from the edge sampling point to the center of the vacuum suction cup under the two-dimensional coordinate axis, which can also be considered as the length of the edge sampling point relative to the center of the vacuum suction cup, and every time it rotates to an edge sampling point, the T-axis encoder will display the angle of the edge sampling point relative to the x-axis, which can also be considered as the angle of the edge sampling point relative to the center of the vacuum suction cup. The laser sensor and T-axis encoder data collected at a fixed time are used as sampling data, and the collected sampling data are stored in a random access memory. In the embodiment of the present invention, only one wafer is required to rotate, and the encoder value can be used to know whether it has rotated one circle. After one circle is rotated, the data sampling is ended, and the wafer slows down and stops rotating after the sampling is ended. When the wafer rotates one circle, the data of each wafer edge sampling point can be just detected.
[0041] Through the above method, the main controller can obtain multiple first sampling data of the edge of the wafer when the wafer rotates one circle, and any first sampling data will include the length and angle of the corresponding sampling point relative to the center of the vacuum chuck.
[0042] Furthermore, the main controller performs derivative processing based on the multiple first sampling data to obtain a derivative value corresponding to each first sampling data, and through the derivative value corresponding to each first sampling data, the second sampling data at the wafer notch is screened out from the multiple first sampling data. Similarly, the remaining sampling data except the second sampling data in the multiple first sampling data can also be screened out. The remaining sampling data is actually the sampling data of the remaining sampling points on the edge of the wafer except the sampling points at the wafer notch.
[0043] Furthermore, the main controller determines the wafer notch position according to the second sampling data, and determines the wafer center position according to the remaining sampling data.
[0044] Furthermore, the main controller controls the X-, Y-, and T-axis motors to calibrate the position of the wafer according to the wafer notch position and the wafer center position, specifically including wafer notch angle adjustment and wafer center position adjustment.
[0045] The wafer calibration method provided by the present invention has a wafer notch located at the edge of the wafer, so second sampling data belonging to the wafer notch can be screened out from the first sampling data of the wafer edge obtained, and the wafer notch position and the wafer center position are located by the second sampling data at the wafer notch. On the basis of the known wafer notch position and the wafer center position, the wafer is accurately calibrated by driving a motor, which can effectively avoid the influence of the mechanical error of the manipulator on the positioning accuracy, and does not require human intervention or manual adjustment, thereby achieving a higher degree of automation, and can provide a more accurate and stable wafer calibration effect, while reducing the number of beats required for wafer calibration, and does not require multiple position adjustments of the wafer, thereby effectively improving production efficiency.
[0046] The following content first describes the process of filtering out the second sampling data of the wafer gap and determining the center position of the wafer according to the remaining sampling data. Figure 5 , Figure 5 It is a schematic diagram of the process of determining the center position of a wafer provided by the present invention.
[0047] In some embodiments, based on step 102, determining the second sampling data of the wafer notch based on the plurality of first sampling data includes: Performing derivative calculation on each first sampling data to obtain multiple derivative values; determining outliers among the plurality of derivative values; The first sampling data used to calculate the outlier value is determined as the second sampling data of the wafer notch.
[0048] Specifically, the main controller performs a derivative calculation on each first sampling data to obtain a plurality of derivative values.
[0049] Specifically, the main controller performs a derivative calculation on each first sampling data by using the following formula: ; Where n represents the nth sampling point; g(n) represents the derivative value corresponding to the nth sampling point; l (n) represents the length corresponding to the nth sampling point; l (n-1) represents the length corresponding to the n-1th sampling point; a(n) represents the angle corresponding to the n-1th sampling point; a(n-1) represents the angle corresponding to the n-1th sampling point.
[0050] Furthermore, the main controller determines the outliers among the multiple derivative values. The statistical method of the 3sigma anomaly detection principle can be used to normally distribute the derivative values after differentiation, and the values beyond the 3sigma range are screened and recorded. The screened values are considered to be outliers.
[0051] The specific process is to distribute multiple derivative values normally. In normal distribution, σ represents the standard deviation, which is an indicator of the degree of dispersion of data distribution. According to the σ principle, the distribution of data in normal distribution is given as follows: about 68% of the data values will fall within the range of one standard deviation (±1σ) from the mean; about 95% of the data values will fall within the range of two standard deviations (±2σ) from the mean; about 99.7% of the data values will fall within the range of three standard deviations (±3σ) from the mean.
[0052] In a normal distribution, data points that are outside three standard deviations (±3σ) of the mean are considered abnormal values or outliers because the probability of these values occurring is very low.
[0053] Therefore, the derivative value g(n) is compared with the normal distribution and the values outside the range of ±3σ are screened out, which are considered to be abnormal and can indicate the wafer notch area.
[0054] Further, the main controller determines the first sampling data used for calculating the outlier as the second sampling data of the wafer notch.
[0055] The embodiment of the present invention first performs a derivative calculation on the first sampling data, and then screens out the outliers in the derivative value, so as to efficiently and accurately determine the second sampling data at the wafer notch, thereby realizing efficient identification and positioning of the wafer notch.
[0056] In some embodiments, based on step 103, determining the center position of the wafer according to the second sampled data includes: Eliminate the second sampling data from the plurality of first sampling data to obtain remaining sampling data; Convert the remaining sampled data into first rectangular coordinates in a first rectangular coordinate system; the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum chuck as the origin; According to the first rectangular coordinate, a circle is fitted; The center of the circle is determined as the center of the wafer, and the coordinates of the center are determined as the position of the center of the wafer.
[0057] Specifically, the main controller removes the second sampling data from the plurality of first sampling data to obtain the remaining sampling data.
[0058] Furthermore, the main controller converts the remaining sampled data into first rectangular coordinates in a first rectangular coordinate system through a trigonometric function transformation formula, wherein the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum suction cup as the origin.
[0059] Furthermore, since the shape of the wafer is a circle, the edge points of the wafer except the notch are all points on the circle. Through the rectangular coordinates corresponding to the points on the circle, a circle can be fitted, and the center of this circle can be considered as the center of the wafer. Therefore, the main controller fits a circle according to the first rectangular coordinate by the least squares method, determines the center of the fitted circle as the center of the wafer, and determines the rectangular coordinates of the center as the position of the center of the wafer.
[0060] The embodiment of the present invention eliminates the second sampling data representing the wafer notch, uses the coordinates of the remaining sampling data in the first rectangular coordinate system to fit a circle model, and then determines the center position of the wafer, thereby achieving efficient identification and positioning of the geometric center of the wafer.
[0061] The following content describes the process of determining the wafer notch position according to the second sampling data. Figure 6 , Figure 6 It is a schematic diagram of the process of determining the wafer notch position provided by the present invention.
[0062] In some embodiments, based on step 103, determining the wafer notch position according to the second sampling data includes: converting the second sampling data into second rectangular coordinates in the first rectangular coordinate system; Subtract the coordinate of the center of the circle from the second rectangular coordinate to obtain a third rectangular coordinate of the second sampling data in a second rectangular coordinate system; the second rectangular coordinate system is a rectangular coordinate system with the center of the wafer as the origin; Convert the third rectangular coordinates into polar coordinates to obtain corrected second sampling data; According to the corrected second sampling data, a quadratic curve is obtained by fitting; Determine the minimum point of the quadratic curve as the lowest point of the wafer notch; The wafer notch position is determined according to the angle of the lowest point of the wafer notch relative to the center of the wafer.
[0063] It should be noted that when the wafer is placed on the vacuum chuck, the center of the wafer and the center of the vacuum chuck are not aligned, so there will be a shift that causes a certain amount of deformation in the original sampling data. Therefore, after obtaining the wafer center coordinate data, the notch sampling data originally in the first rectangular coordinate system with the center of the vacuum chuck as the origin is converted into notch sampling data in the second rectangular coordinate system with the center of the wafer as the origin, so as to correct the notch sampling data and obtain notch sampling data with no deformation in theory. The notch sampling data mentioned above is the second sampling data, and then the wafer notch position is determined based on the corrected notch sampling data. Reference Figure 7 and Figure 8 , Figure 7is the image before the gap sampling data correction provided by the present invention, Figure 8 This is the image after the gap sampling data provided by the present invention is corrected.
[0064] Specifically, the main controller converts the second sampling data into second rectangular coordinates in the first rectangular coordinate system through a trigonometric function transformation formula.
[0065] Furthermore, the main controller subtracts the coordinate of the wafer center from the second rectangular coordinate to obtain a third rectangular coordinate of the second sampling data in the second rectangular coordinate system to eliminate the deformation caused by the displacement between the wafer center and the vacuum chuck center.
[0066] Furthermore, the main controller converts the third rectangular coordinate into a polar coordinate through an inverse transformation formula of a trigonometric function, and determines the length and angle of the wafer notch relative to the center of the wafer through the polar coordinate, which is the corrected second sampling data.
[0067] Furthermore, the main controller fits a quadratic curve by the least square method according to the corrected second sampling data, and determines the minimum point, that is, the lowest point, in the quadratic curve as the lowest point of the wafer notch.
[0068] Furthermore, the main controller determines the angle of the lowest point of the wafer notch relative to the center of the wafer, and determines the position of the wafer notch according to the angle of the lowest point of the wafer notch relative to the center of the wafer.
[0069] The embodiment of the present invention utilizes the coordinates of the second sampling data in the first rectangular coordinate system to subtract the coordinates of the center of the wafer, eliminates the deformation caused by the displacement between the center of the wafer and the center of the vacuum chuck, and realizes the correction of the second sampling data. The corrected second sampling data is used to fit a quadratic curve model, and then the lowest point of the wafer notch is determined to determine the position of the wafer notch, thereby realizing efficient identification and positioning of the wafer notch.
[0070] The following content describes the process of wafer position calibration, which can be referred to Figure 9-11 , Fig. 9 This is one of the schematic diagrams of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention. Fig.10 This is the second schematic diagram of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention. Fig.11 This is the third schematic diagram of the angle deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum chuck provided by the present invention.
[0071] In some embodiments, based on step 104, controlling the driving motor to calibrate the position of the wafer according to the wafer notch position and the wafer center position includes: According to the wafer notch position and the angle compensation value, controlling the driving motor to rotate the wafer notch to a preset angle; According to the center position of the wafer, the driving motor is controlled to move the center of the wafer to a preset position.
[0072] Specifically, the main controller obtains the wafer position instruction issued by the host computer, and the wafer position instruction includes a command to rotate the wafer notch to a specified angle and a command to move the center of the wafer to a specified position.
[0073] In response to the wafer position instruction issued by the host computer, the main controller controls the T-axis motor to rotate the wafer notch to a preset angle according to the wafer notch position and angle compensation value, wherein the preset angle is the angle specified by the host computer.
[0074] At the same time, the main controller controls the X-axis motor and the Y-axis motor to move the center of the wafer to a preset position according to the center position of the wafer, where the preset position is the position specified by the host computer.
[0075] The embodiment of the present invention can effectively avoid the influence of the mechanical error of the robot on the positioning accuracy by driving the motor to calibrate the wafer accurately based on the known wafer notch position and wafer center position, and can achieve a higher degree of automation without human intervention or manual adjustment, and can provide a more accurate and stable wafer calibration effect. At the same time, it reduces the number of cycles required for wafer calibration, and there is no need to adjust the position of the wafer multiple times, thereby effectively improving production efficiency.
[0076] According to the above, the angle compensation value is determined by: Constructing a triangle according to the center position of the wafer, the coordinates of the lowest point and the center position of the vacuum chuck; According to the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated to obtain an angle compensation value.
[0077] It should be noted that there is a two-dimensional coordinate axis by default in the wafer calibration device, and the origin of the coordinate axis is always considered to be the center of the vacuum chuck. When there is a deviation between the origin of the coordinate axis and the center of the wafer, there is always an angle α between the lowest point of the wafer and the coordinate axis, such as Figure 8 shown.
[0078] If the value is not calculated and compensated, the lowest point of the notch found above cannot be aligned with the coordinate axis. If the host computer requires the wafer notch to rotate to 90°, and the main controller does not compensate for this error, the final lowest point of the notch will intersect with the X-axis, rather than the notch pointing in the X-axis direction, as shown below Fig. 9 shown.
[0079] Specifically, the main controller first converts the corrected second sampling data corresponding to the lowest point of the wafer notch into coordinates in the second rectangular coordinate system through a trigonometric function transformation formula, that is, obtains the coordinates of the lowest point of the wafer notch.
[0080] Furthermore, the main controller constructs a triangle according to the center position of the wafer, the coordinates of the lowest point of the wafer notch, and the center position of the vacuum chuck. Fig.10 As shown, the red triangle is the triangle formed by the center of the wafer, the lowest point of the wafer notch and the center of the vacuum chuck, and the angle α to be compensated is the angle between the lowest point of the wafer notch and the x-axis of the first rectangular coordinate system.
[0081] Furthermore, the main controller calculates the angle of the lowest point of the wafer notch relative to the center of the vacuum chuck according to the three sides of the triangle and the trigonometric formula, and uses it as the angle compensation value required when rotating the wafer notch.
[0082] The embodiment of the present invention constructs a triangle with the center of the wafer, the lowest point of the wafer notch and the center of the vacuum suction cup as vertices, and calculates the angle compensation value between the lowest point of the wafer notch and the coordinate axis of the first rectangular coordinate system through the side length of the triangle, thereby achieving precise angle adjustment of the wafer during rotation.
[0083] The main controller provided by the present invention is described below. The main controller described below and the wafer calibration method described above can be referenced to each other.
[0084] Reference Fig.12 , Fig.12 It is a structural schematic diagram of the main controller provided by the present invention.
[0085] The main controller comprises: The acquisition module 1210 is used to acquire a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle.
[0086] The wafer notch data determining module 1220 is configured to determine second sampling data of the wafer notch based on the plurality of first sampling data.
[0087] The position determination module 1230 is used to determine the wafer center position and the wafer notch position according to the second sampling data.
[0088] The control calibration module 1240 is used to control the driving motor to calibrate the position of the wafer according to the wafer notch position and the wafer center position.
[0089] The main controller provided by the present invention can screen out second sampling data belonging to the wafer notch from the first sampling data obtained at the wafer edge because the wafer notch is located at the edge of the wafer. The wafer notch position and the wafer center position are located by the second sampling data at the wafer notch. On the basis of the known wafer notch position and the wafer center position, the wafer is accurately calibrated by driving a motor, which can effectively avoid the influence of the mechanical error of the robot on the positioning accuracy, and does not require human intervention or manual adjustment, thereby achieving a higher degree of automation, and can provide a more accurate and stable wafer calibration effect. At the same time, the number of beats required for wafer calibration is reduced, and there is no need to adjust the position of the wafer multiple times, thereby effectively improving production efficiency.
[0090] Furthermore, the wafer gap data determination module 1220 is also used for: Performing derivative calculation on each first sampling data to obtain multiple derivative values; determining outliers among the plurality of derivative values; The first sampling data used to calculate the outlier value is determined as the second sampling data of the wafer notch.
[0091] Furthermore, the location determination module 1230 is also used for: Eliminate the second sampling data from the plurality of first sampling data to obtain remaining sampling data; Convert the remaining sampled data into first rectangular coordinates in a first rectangular coordinate system; the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum chuck as the origin; According to the first rectangular coordinate, a circle is fitted; The center of the circle is determined as the center of the wafer, and the coordinates of the center are determined as the position of the center of the wafer.
[0092] Furthermore, the location determination module 1230 is also used for: converting the second sampling data into second rectangular coordinates in the first rectangular coordinate system; Subtract the coordinate of the center of the circle from the second rectangular coordinate to obtain a third rectangular coordinate of the second sampling data in a second rectangular coordinate system; the second rectangular coordinate system is a rectangular coordinate system with the center of the wafer as the origin; Convert the third rectangular coordinates into polar coordinates to obtain corrected second sampling data; According to the corrected second sampling data, a quadratic curve is obtained by fitting; Determine the minimum point of the quadratic curve as the lowest point of the wafer notch; The wafer notch position is determined according to the angle of the lowest point of the wafer notch relative to the center of the wafer.
[0093] Furthermore, the control calibration module 1240 is also used for: According to the wafer notch position and the angle compensation value, controlling the driving motor to rotate the wafer notch to a preset angle; According to the center position of the wafer, the driving motor is controlled to move the center of the wafer to a preset position.
[0094] Furthermore, the main controller is also used for: Constructing a triangle according to the center position of the wafer, the coordinates of the lowest point and the center position of the vacuum chuck; According to the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated to obtain an angle compensation value.
[0095] It should be noted that the main controller provided by the present invention can execute the wafer calibration method described in any of the above embodiments during specific operation, which will not be elaborated in this embodiment.
[0096] Fig.13 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Fig.13 As shown, the electronic device may include: a processor 1310, a communication interface 1320, a memory 1330 and a communication bus 1340, wherein the processor 1310, the communication interface 1320 and the memory 1330 communicate with each other through the communication bus 1340. The processor 1310 may call the logic instructions in the memory 1330 to execute the wafer calibration method, which includes: obtaining a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; determining the second sampling data of the wafer notch based on the plurality of first sampling data; determining the wafer center position and the wafer notch position according to the second sampling data; and controlling the drive motor to perform position calibration on the wafer according to the wafer notch position and the wafer center position.
[0097] In addition, the logic instructions in the above-mentioned memory 1330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.
[0098] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the wafer calibration method provided in the above-mentioned embodiments, and the method includes: obtaining multiple first sampling data of the edge of the wafer when the wafer rotates one circle; based on the multiple first sampling data, determining the second sampling data of the wafer notch; according to the second sampling data, determining the wafer center position and the wafer notch position; according to the wafer notch position and the wafer center position, controlling the drive motor to calibrate the wafer position.
[0099] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute the wafer calibration method provided in the above-mentioned embodiments, the method comprising: obtaining multiple first sampling data of the edge of the wafer when the wafer rotates one circle; based on the multiple first sampling data, determining second sampling data of the wafer notch; according to the second sampling data, determining the wafer center position and the wafer notch position; according to the wafer notch position and the wafer center position, controlling the drive motor to calibrate the position of the wafer.
[0100] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Those of ordinary skill in the art may understand and implement the present invention without creative effort.
[0101] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.
[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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 do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A wafer calibration method, characterized in that: Applicable to main controller, including: Acquire a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; Based on the plurality of first sampling data, determining second sampling data of the wafer notch; Determine the wafer center position and the wafer notch position according to the second sampling data; According to the wafer notch position and the wafer center position, a driving motor is controlled to perform position calibration on the wafer.
2. The wafer calibration method according to claim 1, characterized in that: The step of determining second sampling data of the wafer notch based on the plurality of first sampling data comprises: Performing derivative calculation on each first sampling data to obtain multiple derivative values; determining outliers among the plurality of derivative values; The first sampling data used to calculate the outlier value is determined as the second sampling data of the wafer notch.
3. The wafer calibration method according to claim 2, characterized in that: The wafer is driven to rotate by the vacuum chuck; any of the first sampling data includes the length and angle of the sampling point relative to the center of the vacuum chuck; the derivative calculation of each first sampling data is calculated by the following formula: ； Where n represents the nth sampling point; g(n) represents the derivative value corresponding to the nth sampling point; l (n) represents the length corresponding to the nth sampling point; l (n-1) represents the length corresponding to the n-1th sampling point; a(n) represents the angle corresponding to the n-1th sampling point; a(n-1) represents the angle corresponding to the n-1th sampling point.
4. The wafer calibration method according to claim 3, characterized in that: Determining the center position of the wafer according to the second sampling data includes: Eliminate the second sampling data from the plurality of first sampling data to obtain remaining sampling data; Convert the remaining sampled data into first rectangular coordinates in a first rectangular coordinate system; the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum chuck as the origin; According to the first rectangular coordinate, a circle is fitted; The center of the circle is determined as the center of the wafer, and the coordinates of the center are determined as the position of the center of the wafer.
5. The wafer calibration method according to claim 4, characterized in that: Determining the wafer notch position according to the second sampling data includes: converting the second sampling data into second rectangular coordinates in the first rectangular coordinate system; Subtract the coordinate of the center of the circle from the second rectangular coordinate to obtain a third rectangular coordinate of the second sampling data in a second rectangular coordinate system; the second rectangular coordinate system is a rectangular coordinate system with the center of the wafer as the origin; Convert the third rectangular coordinates into polar coordinates to obtain corrected second sampling data; According to the corrected second sampling data, a quadratic curve is obtained by fitting; Determine the minimum point of the quadratic curve as the lowest point of the wafer notch; The wafer notch position is determined according to the angle of the lowest point of the wafer notch relative to the center of the wafer.
6. The wafer calibration method according to claim 5, characterized in that: According to the wafer notch position and the wafer center position, controlling the driving motor to perform position calibration on the wafer comprises: According to the wafer notch position and the angle compensation value, controlling the driving motor to rotate the wafer notch to a preset angle; According to the center position of the wafer, the driving motor is controlled to move the center of the wafer to a preset position.
7. The wafer calibration method according to claim 6, characterized in that: The angle compensation value is determined by: Constructing a triangle according to the center position of the wafer, the coordinates of the lowest point and the center position of the vacuum chuck; According to the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated to obtain an angle compensation value.
8. A main controller, characterized in that: include: An acquisition module, used for acquiring a plurality of first sampling data of the edge of the wafer when the wafer rotates one circle; A wafer notch data determination module, configured to determine second sampling data of the wafer notch based on the plurality of first sampling data; A position determination module, used for determining the center position of the wafer and the wafer notch position according to the second sampling data; The control calibration module is used to control the driving motor to perform position calibration on the wafer according to the wafer notch position and the wafer center position.
9. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the wafer calibration method according to any one of claims 1 to 7 are implemented.
10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the wafer calibration method according to any one of claims 1 to 7 are implemented.