Wafer alignment method, main controller, electronic equipment, and storage medium

Abstract

This invention provides a wafer alignment method, main controller, electronic equipment, and storage medium that effectively avoid the effects of machine differences in manipulators, eliminate the need for human intervention or manual adjustment, achieve a higher level of automation, provide a more precise and stable wafer alignment effect, reduce the number of cycles required for wafer alignment, eliminate the need for multiple position adjustments to the wafer, and improve production efficiency. [Solution] The method involves acquiring multiple data points of the wafer edge as the wafer rotates once, determining the sampling data of the wafer notch based on this sampling data, determining the wafer center position and wafer notch position based on the notch sampling data, and performing position alignment based on the wafer notch position and wafer center position. After the wafer notch position and wafer center position are already known, precise position alignment is performed on the wafer using a drive motor.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and more particularly, to a wafer alignment method, a main controller, an electronic device, and a storage medium.

Background Art

[0002] With the development of industrial technology, the requirements for the efficiency and accuracy of semiconductor device manufacturing are increasing. A wafer is a basic material for semiconductor device manufacturing, generally made of silicon, and a fine circuit structure is formed by high-purity processing. Wafer alignment is an essential part of semiconductor device manufacturing and is directly related to the performance and reliability of products.

[0003] In the prior art, generally, a manipulator is used to transfer a wafer from one process position to another process position, and the wafer is placed at a predetermined position of a process device while repeatedly adjusting. However, the alignment by the manipulator depends on the accuracy and stability of the mechanical device, and due to the wear, vibration, and elastic deformation of the mechanical system, a certain error will occur in wafer alignment.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a wafer alignment method, a main controller, an electronic device, and a storage medium to solve the problem of low accuracy when implementing wafer alignment by a manipulator in the prior art.

Means for Solving the Problems

[0005] In a first aspect, the present invention provides a wafer alignment method, acquiring a plurality of first sampling data of a wafer edge when the wafer rotates one full turn, determining second sampling data of a wafer notch based on the plurality of first sampling data, Based on the second sampling data, the wafer center position and wafer notch position are determined, This includes controlling a drive motor based on the wafer notch position and the wafer center position to perform positional alignment with respect to the wafer.

[0006] In one embodiment, determining the second sampling data of the wafer notch based on the plurality of first sampling data described above is: Perform differential calculations on each first sample data to obtain multiple derivative values, Determining the outlier among the aforementioned multiple differential values, This includes determining the first sampling data for calculating the outliers as the second sampling data for the wafer notch.

[0007] In one embodiment, the wafer is driven and rotated by a vacuum suction cup, and each of the first sampling data includes the length and angle of the sampling point with respect to the center of the vacuum suction cup, and the differential calculation performed on each of the first sampling data is calculated by the following formula:

number

[0008] In one embodiment, determining the wafer center position based on the second sampling data is: The process involves removing the second sampling data from the plurality of first sampling data to obtain the remaining sampling data. The remaining sampled data is transformed into a first Cartesian coordinate system, wherein the first Cartesian coordinate system is a Cartesian coordinate system with the center of the vacuum suction cup as the origin. Based on the aforementioned first Cartesian coordinates, fitting is performed to obtain a single circle, This includes determining the center of the circle as the wafer center and determining the coordinates of the center as the wafer center position.

[0009] In one embodiment, determining the wafer notch position based on the second sampling data is: Converting the second sampling data into a second Cartesian coordinate system in the first Cartesian coordinate system, The method involves subtracting the coordinates of the center of the wafer from the second Cartesian coordinates to obtain the third Cartesian coordinates of the second sampling data in the second Cartesian coordinate system, wherein the second Cartesian coordinate system is a Cartesian coordinate system with the center of the wafer as the origin. Convert the third rectangular coordinates to polar coordinates and obtain the corrected second sampling data, Based on the corrected second sampling data, a quadratic curve is obtained by fitting, The minimum point of the quadratic curve is determined as the lowest point of the wafer notch, The method includes determining the wafer notch position based on the angle of the lowest point of the wafer notch with respect to the wafer center.

[0010] In one embodiment, controlling the drive motor based on the wafer notch position and the wafer center position to perform positional alignment with the wafer is, Based on the wafer notch position and angle correction value, the drive motor is controlled to rotate the wafer notch to a preset angle. This includes controlling a drive motor to move the wafer center to a preset position based on the wafer center position.

[0011] In one embodiment, the angle correction value is determined by the following method: Based on the wafer's center position, the coordinates of the lowest point, and the vacuum suction cup's center position, a triangle is constructed. Based on the side lengths of the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated, and an angle correction value is obtained.

[0012] In a second aspect, the present invention further provides a main controller, An acquisition module configured to acquire multiple first sample data of the wafer edge as the wafer rotates once, A wafer notch data determination module configured to determine second sampling data of a wafer notch based on the plurality of first sampling data, A position determination module configured to determine the wafer center position and wafer notch position based on the second sampling data, The system includes a control alignment module configured to control a drive motor to perform positional alignment with respect to the wafer based on the wafer notch position and the wafer center position.

[0013] In a third embodiment, 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, it realizes the steps in the wafer alignment method described in any one of the above paragraphs.

[0014] In a fourth embodiment, the present invention further provides a non-temporary computer-readable storage medium in which a computer program is stored, and when the computer program is executed by a processor, the steps of the wafer alignment method described in any one of the above paragraphs are realized. [Effects of the Invention]

[0015] The wafer alignment method, main controller, electronic device, and storage medium according to the present invention are such that since the wafer notch is located at the edge of the wafer, the second sampling data belonging to the wafer notch position is selected from the acquired first sampling data of the wafer edge, and the wafer notch position and the wafer center position are positioned by the second sampling data at the wafer notch position. After the wafer notch position and the wafer center position are already known, precise position alignment is performed on the wafer by a drive motor, thereby effectively avoiding the influence on the positioning accuracy due to the mechanical error of the manipulator, and eliminating the need for artificial intervention or manual adjustment, realizing a higher degree of automation, providing a more precise and stable wafer alignment effect, reducing the number of tact times required for wafer alignment, eliminating the need for multiple position adjustments for the wafer, and effectively improving the production efficiency.

Brief Description of the Drawings

[0016] Hereinafter, in order to more clearly explain the technical solutions in the present invention or the prior art, the drawings necessary for the description of the embodiments or the prior art will be briefly described. Of course, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0017] [Figure 1] It is a flowchart of the wafer alignment method according to the present invention. [Figure 2] It is a schematic diagram of the wafer alignment device according to the present invention. [Figure 3] It is a control logic flowchart according to the present invention. [Figure 4] It is a data collection flowchart according to the present invention. [Figure 5] It is a flowchart for determining the wafer center position according to the present invention. [Figure 6] It is a flowchart for determining the wafer notch position according to the present invention. [Figure 7]This is an image of the notch sampling data before correction according to the present invention. [Figure 8] This is a corrected image of notch sampling data according to the present invention. [Figure 9] This is a schematic diagram (part 1) of the angular deviation between the lowest point of the wafer notch according to the present invention and the coordinate axes of the vacuum suction cup. [Figure 10] This is a schematic diagram (part 2) of the angular deviation between the lowest point of the wafer notch according to the present invention and the coordinate axis of the vacuum suction cup. [Figure 11] This is a schematic diagram (part 3) of the angular deviation between the lowest point of the wafer notch according to the present invention and the coordinate axis of the vacuum suction cup. [Figure 12] This is a schematic diagram of the structure of the main controller according to the present invention. [Figure 13] This is a schematic diagram of the structure of the electronic device according to the present invention. [Modes for carrying out the invention]

[0018] Hereinafter, in order to further clarify the object, technical proposal, and advantages of the present invention, the technical proposal of the present invention will be clearly and completely described with reference to the drawings of the present invention. Of course, the embodiments described are not all embodiments, but only some embodiments of the present invention. All other embodiments that a person skilled in the art may obtain without creative work based on the embodiments of the present invention are all within the scope of protection of the present invention.

[0019] The terms "first," "second," etc., used in this invention are for distinguishing similar objects and are not intended to describe a specific order or sequence. The data used in this manner are interchangeable where appropriate, so that embodiments of the invention may be carried out in an order other than those illustrated or described herein.

[0020] The wafer alignment method, main controller, electronic device, and storage medium according to the present invention will be described below with reference to Figures 1-13.

[0021] Referring to Figure 1, Figure 1 is a flowchart of the wafer alignment method according to the present invention.

[0022] As shown in Figure 1, the method includes the following steps 101 to 104. In step 101, multiple first sample data of the wafer edge are obtained as the wafer rotates once. In step 102, second sampling data of the wafer notch is determined based on the plurality of first sampling data. In step 103, the wafer center position and the wafer notch position are determined based on the second sampling data. In step 104, the drive motor is controlled based on the wafer notch position and the wafer center position to perform position alignment with respect to the wafer.

[0023] The wafer alignment method according to the embodiment of the present invention is implemented based on a wafer alignment apparatus. As shown in Figure 2, Figure 2 is a schematic diagram of the wafer alignment apparatus according to the present invention. As can be seen from Figure 2, the wafer alignment apparatus mainly includes a main controller, a laser sensor, a vacuum suction cup, and X-axis, Y-axis, and T-axis motors (drive motors). Here, the vacuum suction cup is used to drive the wafer to rotate by fixing it after the wafer has been placed, the laser sensor is used to drive the wafer to rotate a full circle and to continuously detect the wafer's edge during rotation, of the X-axis, Y-axis, and T-axis motors, the X-axis motor is generally responsible for moving along the left-right direction (or the front-back direction depending on the definition of the coordinate system) on the horizontal plane, the Y-axis motor is generally responsible for moving along the front-back direction (or the left-right direction depending on the definition of the coordinate system) on the horizontal plane, and the T-axis motor is generally responsible for the rotational motion of the vacuum suction cup, which drives the wafer to rotate along with it, allowing the wafer's angle to be adjusted, the main controller periodically collects data detected by the laser sensor, processes the collected data after data collection is complete, analyzes the wafer notch position and wafer center position, and finally drives the X-axis, Y-axis, and T-axis motors to rotate the wafer notch to an angle specified by the host computer and move the wafer center to a position specified by the host computer. The control logic steps can be seen in Figure 3, which is a control logic flowchart according to the present invention.

[0024] The wafer alignment method according to the present invention mainly involves processing collected edge sampling data to analyze the wafer notch position and wafer center position, and further controlling a drive motor to perform positional alignment on the wafer based on the wafer notch position and wafer center position. In other words, the wafer alignment method according to the present invention is mainly implemented by a main controller. Therefore, an embodiment of the present invention will describe the wafer alignment method using the main controller in a wafer alignment apparatus as the execution unit, as an example.

[0025] Specifically, the wafer alignment device must be initialized before operation. If initialization is not performed, operation will not be permitted. This prevents data stored during the previous operation from affecting the current operation.

[0026] After initialization is complete, when starting operation, the wafer is first placed on the vacuum suction cup. The wafer alignment device opens the vacuum valve to suction the wafer, and then drives the vacuum suction cup to rotate the wafer one full turn. During the rotation process, the laser sensor continuously detects the wafer edge. The laser sensor may be a line laser sensor or can be replaced with other similar products. As long as the final output is the detected value of the wafer edge, positional alignment can be performed on the wafer using this method.

[0027] During the process in which the laser sensor detects the wafer edge, the main controller periodically collects and stores the data detected by the laser sensor. As a result, the main controller can sample thousands or even tens of thousands of points based on the automatic alignment cycle time set by the user.

[0028] Referring to Figure 4, which is a data acquisition flowchart according to the present invention. Specifically, after the alignment process is started, the T-axis motor starts rotating, and after the T-axis motor transitions to constant velocity motion, the main controller starts a timer and periodically collects data from the laser sensor and T-axis encoder based on the timer. The wafer alignment apparatus has one 2D coordinate axis by default, and the origin of this 2D 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 on the 2D coordinate axis to the center of the vacuum suction cup, and may be considered to be the length of the edge sampling point relative to the center of the vacuum suction cup. Furthermore, each time the wafer rotates to an edge sampling point, the angle of the edge sampling point with respect to the x-axis is displayed on the T-axis encoder, and may be considered to be the angle of the edge sampling point relative to the center of the vacuum suction cup. The periodically collected data from the laser sensor and T-axis encoder is stored as sampled data in random access memory. In the embodiment of the present invention, it is sufficient to rotate the wafer once, and it is possible to determine whether or not the rotation has been completed by the encoder value. After the rotation is complete, data sampling is terminated, and after sampling is terminated, the wafer is decelerated and the rotation is stopped. Once the wafer has rotated once, it is possible to detect data at the sampling points of each wafer edge.

[0029] Using the above method, the main controller can acquire multiple first sampling data of the wafer edge as the wafer rotates once, and each of the first sampling data includes the length and angle of the vacuum suction cup relative to the center of the corresponding sampling point.

[0030] Furthermore, the main controller performs differential processing based on multiple first sampling data to obtain the derivative value corresponding to each first sampling data. Using the derivative value corresponding to each first sampling data, it selects the second sampling data at the wafer notch position from the multiple first sampling data, and at the same time, it can also select the remaining sampling data from the multiple first sampling data other than the second sampling data. The remaining sampling data is actually the sampling data from the remaining sampling points on the wafer edge other than the sampling point at the wafer notch position.

[0031] Furthermore, the main controller determines the wafer notch position based on the second sampling data and the wafer center position based on the remaining sampling data.

[0032] Furthermore, the main controller controls the X-axis, Y-axis, and T-axis motors based on the wafer notch position and wafer center position to perform positional alignment with the wafer, specifically including wafer notch angle adjustment and wafer center position adjustment.

[0033] The wafer alignment method according to the present invention, since the wafer notch is located at the edge of the wafer, selects second sampling data belonging to the wafer notch position from first sampling data of the acquired wafer edge, positions the wafer notch position and the wafer center position using the second sampling data at the wafer notch position, and performs precise position alignment on the wafer with a drive motor after already knowing the wafer notch position and the wafer center position. This effectively avoids the influence of manipulator errors on positioning accuracy, eliminates the need for human intervention or manual adjustment, enables a higher level of automation, provides a more precise and stable wafer alignment effect, reduces the number of cycles required for wafer alignment, and eliminates the need to perform position adjustments on the wafer multiple times, thereby effectively improving production efficiency.

[0034] The following describes the process of first selecting the second sampling data of the wafer notch and then determining the wafer center position based on the remaining sampling data, and you can refer to Figure 5, which is a flowchart for determining the wafer center position according to the present invention.

[0035] In some embodiments, based on step 102, a second sampling data of the wafer notch is determined based on the plurality of first sampling data described above. Perform differential calculations on each first sample data to obtain multiple derivative values, Determining the outlier among the aforementioned multiple differential values, This includes determining the first sampling data for calculating the outliers as the second sampling data for the wafer notch.

[0036] Specifically, the main controller performs differential calculations on each first sample data to obtain multiple derivative values.

[0037] Specifically, the main controller performs a differential calculation on each first sample data point, which is calculated using the following formula:

number

[0038] Furthermore, when the main controller determines an outlier among multiple derivative values, it can use a statistical method based on the 3-sigma anomaly detection principle to normalize the derivative values ​​after differentiation, select and record values ​​that exceed the 3-sigma range, and consider the selected values ​​to be outliers.

[0039] In concrete terms, multiple derivative values ​​are distributed in a normal distribution, where σ represents the standard deviation and is an indicator of the degree of variance in the data distribution. Based on the σ principle, the following is an example of the distribution of data in a normal distribution: Approximately 68% of the data values ​​fall within one standard deviation (±1σ) from the mean, approximately 95% of the data values ​​fall within two standard deviations (±2σ) from the mean, and approximately 99.7% of the data values ​​fall within three standard deviations (±3σ) from the mean.

[0040] In a normal distribution, data points that fall outside the range of three standard deviations (±3σ) from the mean are considered outliers or abnormal values ​​because their probability of occurrence is extremely low.

[0041] Therefore, by comparing the differential value g(n) with the normal distribution and selecting values ​​that exceed the ±3σ range, these values ​​are considered abnormal and can indicate the wafer notch region.

[0042] Furthermore, the main controller determines the first sampling data for calculating outliers as the second sampling data for the wafer notch.

[0043] In embodiments of the present invention, a differential calculation is first performed on the first sampling data, and outliers among the differential values ​​are selected, thereby efficiently and relatively accurately determining the second sampling data at the wafer notch position, and further achieving efficient identification and positioning of the wafer notch.

[0044] In some embodiments, determining the wafer center position based on the second sampling data according to step 103 is: The process involves removing the second sampling data from the plurality of first sampling data to obtain the remaining sampling data. The remaining sampled data is transformed into a first Cartesian coordinate system, wherein the first Cartesian coordinate system is a Cartesian coordinate system with the center of the vacuum suction cup as the origin. Based on the aforementioned first Cartesian coordinates, fitting is performed to obtain a single circle, This includes determining the center of the circle as the wafer center and determining the coordinates of the center as the wafer center position.

[0045] Specifically, the main controller removes the second sample data from multiple first sample data to obtain the remaining sample data.

[0046] Furthermore, the main controller uses a trigonometric function transformation formula to convert the remaining sampled data into a first rectangular coordinate system, where the first rectangular coordinate system is a rectangular coordinate system with the center of the vacuum suction cup as the origin.

[0047] Furthermore, since the wafer is circular in shape, all wafer edge points, excluding the notch, lie on the circumference. A circle can be fitted from the Cartesian coordinates corresponding to these points on the circumference, and the center of this circle is considered to be the wafer center. Therefore, the main controller fits a circle using the least squares method based on the first Cartesian coordinates, determines the center of the fitted circle as the wafer center, and determines the Cartesian coordinates of the center as the wafer center position.

[0048] Embodiments of the present invention remove second sampling data representing wafer notches, fit a circle model using the coordinates of the remaining sampling data in a first Cartesian coordinate system, and further determine the wafer center position, thereby achieving efficient identification and positioning relative to the geometric center of the wafer.

[0049] The following describes the process of determining the wafer notch position based on the second sampling data, and you can refer to Figure 6, which is a flowchart for determining the wafer notch position according to the present invention.

[0050] In some embodiments, determining the wafer notch position based on the second sampling data according to step 103 is: Converting the second sampling data into a second Cartesian coordinate system in the first Cartesian coordinate system, The method involves subtracting the coordinates of the center of the wafer from the second Cartesian coordinates to obtain the third Cartesian coordinates of the second sampling data in the second Cartesian coordinate system, wherein the second Cartesian coordinate system is a Cartesian coordinate system with the center of the wafer as the origin. Convert the third rectangular coordinates to polar coordinates and obtain the corrected second sampling data, Based on the corrected second sampling data, a quadratic curve is obtained by fitting, The minimum point of the quadratic curve is determined as the lowest point of the wafer notch, The method includes determining the wafer notch position based on the angle of the lowest point of the wafer notch with respect to the wafer center.

[0051] When a wafer is placed on a vacuum suction cup, the center of the wafer and the center of the vacuum suction cup are not aligned, resulting in a positional shift and a certain amount of deformation in the original sampling data. Therefore, after obtaining the coordinate data of the wafer center, the notch sampling data in the first rectangular coordinate system, which originally had the center of the vacuum suction cup as the origin, is converted to notch sampling data in a second rectangular coordinate system, which also has the center of the wafer as the origin. This corrects the notch sampling data, thereby obtaining notch sampling data that theoretically has no deformation. The above notch sampling data is the second sampling data, and the wafer notch position is determined based on the corrected notch sampling data. Referring to Figures 7 and 8, Figure 7 is an image of the notch sampling data before correction according to the present invention, and Figure 8 is an image of the notch sampling data after correction according to the present invention.

[0052] Specifically, the main controller converts the second sampled data into second rectangular coordinates in the first rectangular coordinate system using a trigonometric function transformation formula.

[0053] Furthermore, the main controller subtracts the coordinates of the wafer center from the second rectangular coordinate system to obtain the third rectangular coordinate system of the second sampling data, thereby removing the deformation caused by the misalignment between the wafer center and the vacuum suction cup center.

[0054] Furthermore, the main controller converts the third Cartesian coordinates to polar coordinates using an inverse trigonometric function transformation formula, and determines the length and angle of the wafer notch relative to the wafer center through the polar coordinates; this is the corrected second sampling data.

[0055] Furthermore, the main controller fits a quadratic curve using the least squares method based on the corrected second sampling data, and determines the minimum point of the quadratic curve, i.e., the lowest point, as the lowest point of the wafer notch.

[0056] Furthermore, the main controller determines the angle of the lowest point of the wafer notch with respect to the wafer center, and determines the wafer notch position based on the angle of the lowest point of the wafer notch with respect to the wafer center.

[0057] Embodiments of the present invention remove deformation due to misalignment between the wafer's center and the vacuum suction cup's center by subtracting the coordinates of the wafer's center from the coordinates of the second sampling data in the first Cartesian coordinate system, thereby correcting the second sampling data. The corrected second sampling data is then used to fit a quadratic curve model, further determining the lowest point of the wafer notch, thereby determining the wafer notch position and achieving efficient identification and positioning of the wafer notch.

[0058] The following describes the wafer position alignment process, referring to Figures 9-11. Figure 9 is a schematic diagram (1) of the angular deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum suction cup according to the present invention. Figure 10 is a schematic diagram (2) of the angular deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum suction cup according to the present invention. Figure 11 is a schematic diagram (3) of the angular deviation between the lowest point of the wafer notch and the coordinate axis of the vacuum suction cup according to the present invention.

[0059] In some embodiments, based on step 104, the drive motor is controlled to perform positional alignment with the wafer based on the wafer notch position and the wafer center position as described above. Based on the wafer notch position and angle correction value, the drive motor is controlled to rotate the wafer notch to a preset angle. This includes controlling a drive motor to move the wafer center to a preset position based on the wafer center position.

[0060] Specifically, the main controller acquires a wafer position command issued by the host computer, and the wafer position command includes a command to rotate the wafer notch to a specified angle and a command to move the wafer center to a predetermined position.

[0061] In response to a wafer position command issued by the host computer, the main controller controls the T-axis motor to rotate the wafer notch to a preset angle based on the wafer notch position and angle correction value, where the preset angle is the angle specified by the host computer.

[0062] Simultaneously, the main controller controls the X-axis and Y-axis motors based on the wafer's center position to move the wafer's center to a preset position, where the preset position is specified by the host computer.

[0063] Embodiments of the present invention, by performing precise positional alignment on the wafer using a drive motor after already knowing the wafer notch position and wafer center position, effectively avoid the impact of manipulator errors on positioning accuracy, eliminate the need for human intervention or manual adjustment, enable a higher level of automation, provide a more precise and stable wafer alignment effect, reduce the number of cycles required for wafer alignment, and eliminate the need to perform multiple positional adjustments on the wafer, thereby effectively improving production efficiency.

[0064] Based on the above, the angle correction value is determined by the following method: Based on the wafer's center position, the coordinates of the lowest point, and the vacuum suction cup's center position, a triangle is constructed. Based on the side lengths of the three sides of the triangle, the angle of the lowest point relative to the center of the vacuum suction cup is calculated, and an angle correction value is obtained.

[0065] It should be noted that a wafer alignment device has one 2D coordinate axis by default, and the origin of that coordinate axis is always considered to be the center of the vacuum suction cup. If the origin of the coordinate axis and the wafer's center are misaligned, an angle α always exists between the lowest point of the wafer and the coordinate axis, as shown in Figure 9.

[0066] Without compensation calculations for this value, the lowest point of the notch found above cannot be aligned with the coordinate axes. If the host computer requests that the wafer notch be rotated 90°, and the main controller does not perform compensation calculations for this error, the lowest point of the notch will ultimately intersect the X-axis, rather than the notch being oriented in the X-axis direction, as shown in Figure 10 below.

[0067] Specifically, the main controller first uses a trigonometric function transformation formula to convert the corrected second sampling data corresponding to the lowest point of the wafer notch into coordinates in a second Cartesian coordinate system, that is, to obtain the coordinates of the lowest point of the wafer notch.

[0068] Furthermore, the main controller constructs a triangle based on the wafer center position, the coordinates of the lowest point of the wafer notch, and the vacuum suction cup center position. As shown in Figure 11, this triangle is enclosed by the wafer center, the lowest point of the wafer notch, and the vacuum suction cup center, 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 Cartesian coordinate system.

[0069] Furthermore, the main controller uses trigonometric functions based on the lengths of the three sides of the triangle to calculate the angle of the lowest point of the wafer notch relative to the center of the vacuum suction cup, and uses this as the angle correction value required when rotating the wafer notch.

[0070] In embodiments of the present invention, a triangle is constructed with the wafer center, the lowest point of the wafer notch, and the vacuum suction cup center as its vertices. By calculating the angle correction value between the lowest point of the wafer notch and the coordinate axes of the first Cartesian coordinate system through the side lengths of the triangle, accurate angle adjustment during the wafer rotation process is achieved.

[0071] The following describes the main controller according to the present invention, and the main controller described below can be referred to in correspondence with the wafer alignment method described above.

[0072] Referring to Figure 12, which is a schematic diagram of the structure of the main controller according to the present invention.

[0073] The aforementioned main controller An acquisition module 1210 is configured to acquire multiple first sample data of the wafer edge as the wafer rotates once, A wafer notch data determination module 1220 is configured to determine second sampling data of a wafer notch based on the plurality of first sampling data, A position determination module 1230 is configured to determine the wafer center position and wafer notch position based on the second sampling data, The system includes a control alignment module 1240 configured to control a drive motor to perform position alignment with respect to the wafer based on the wafer notch position and the wafer center position.

[0074] The main controller according to the present invention, since the wafer notch is located at the edge of the wafer, selects second sampling data belonging to the wafer notch position from first sampling data of the acquired wafer edge, positions the wafer notch position and the wafer center position using the second sampling data at the wafer notch position, and, having already determined the wafer notch position and the wafer center position, performs precise position alignment on the wafer with a drive motor. This effectively avoids the impact of manipulator errors on positioning accuracy, eliminates the need for human intervention or manual adjustment, enables a higher level of automation, provides a more precise and stable wafer alignment effect, reduces the number of cycles required for wafer alignment, and eliminates the need to perform multiple position adjustments on the wafer, thereby effectively improving production efficiency.

[0075] Furthermore, the wafer notch data determination module 1220 further, Perform differential calculations on each first sample data to obtain multiple derivative values, Determining the outlier among the aforementioned multiple differential values, This is used to determine the first sampling data for calculating the outliers as the second sampling data for the wafer notch.

[0076] Furthermore, the position determination module 1230 further, The process involves removing the second sampling data from the plurality of first sampling data to obtain the remaining sampling data. The remaining sampled data is transformed into a first Cartesian coordinate system, wherein the first Cartesian coordinate system is a Cartesian coordinate system with the center of the vacuum suction cup as the origin. Based on the aforementioned first Cartesian coordinates, fitting is performed to obtain a single circle, This is used to determine the center of the circle as the wafer center and to determine the coordinates of the center as the wafer center position.

[0077] Furthermore, the position determination module 1230 further, Converting the second sampling data into a second Cartesian coordinate system in the first Cartesian coordinate system, The method involves subtracting the coordinates of the center of the wafer from the second Cartesian coordinates to obtain the third Cartesian coordinates of the second sampling data in the second Cartesian coordinate system, wherein the second Cartesian coordinate system is a Cartesian coordinate system with the center of the wafer as the origin. Convert the third rectangular coordinates to polar coordinates and obtain the corrected second sampling data, Based on the corrected second sampling data, a quadratic curve is obtained by fitting, The minimum point of the quadratic curve is determined as the lowest point of the wafer notch, This is used to determine the wafer notch position based on the angle of the lowest point of the wafer notch with respect to the wafer center.

[0078] Furthermore, the control alignment module 1240 further, Based on the wafer notch position and angle correction value, the drive motor is controlled to rotate the wafer notch to a preset angle. It is used to control the drive motor based on the wafer center position to move the wafer center to a preset position.

[0079] Furthermore, the main controller further, A triangle is constructed based on the wafer's center position, the coordinates of the lowest point, and the vacuum suction cup's center position. This is used to calculate the angle of the lowest point relative to the center of the vacuum suction cup based on the side lengths of the three sides of the triangle, and to obtain an angle correction value.

[0080] Furthermore, the main controller according to the present invention can execute the wafer alignment method described in any of the above embodiments when it is in operation, and this embodiment will omit further explanation of this.

[0081] Figure 13 is a schematic diagram of the structure of an electronic device according to the present invention. As shown in Figure 13, the electronic device may include a processor 1310, a communications interface 1320, a memory 1330, and a communications bus 1340. Here, the processor 1310, the communications interface 1320, and the memory 1330 communicate with each other via the communications bus 1340. The processor 1310 can call a logic instruction in the memory 1330 to execute a wafer alignment method. This method includes acquiring a plurality of first sampling data of the wafer edge when the wafer rotates once, determining 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 based on the second sampling data, and controlling a drive motor to perform position alignment with the wafer based on the wafer notch position and the wafer center position.

[0082] Furthermore, the logical instructions in the memory 1330 may be implemented in the form of software function units and, if sold or used as independent products, can be stored in a processor-readable storage medium. Based on this understanding, the technical proposal of the present invention may be embodied in the form of a software product, either in its essence, in a part that contributes to the prior art, or in a part of the technical means. The computer software product is stored in a storage medium and includes several instructions that 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 method described in each embodiment of the present invention. The storage medium includes various media capable of storing program code, such as U disks, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0083] On the other hand, the present invention further provides a computer program product which includes a computer program stored on a non-temporary computer-readable storage medium, the computer program includes program instructions, and when the program instructions are executed by a computer, the computer can perform a wafer alignment method according to each of the above embodiments, the method comprising: acquiring a plurality of first sampling data of the wafer edge as the wafer rotates once; determining 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 based on the second sampling data; and controlling a drive motor to perform position alignment with the wafer based on the wafer notch position and the wafer center position.

[0084] On the other hand, the present invention further provides a non-temporary computer-readable storage medium in which a computer program is stored, and which, when executed by a processor, causes the wafer alignment method according to each of the above embodiments to be executed, the method comprising: acquiring a plurality of first sampling data of the wafer edge when the wafer rotates once; determining 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 based on the second sampling data; and controlling a drive motor to perform position alignment with the wafer based on the wafer notch position and the wafer center position.

[0085] The embodiments of the apparatus described above are merely illustrative. Units described here as separate components may or may not be physically separate, and components shown as units may or may not be physical units. The objective of the technical solution of this embodiment can be achieved by adopting some or all of the units according to the actual needs. Those skilled in the art can understand and implement it without any creative work.

[0086] As will be apparent to those skilled in the art from the above description of the embodiments, each embodiment may be implemented by combining software and a necessary common hardware platform, or of course, by hardware. Based on this understanding, the above invention can be embodied in the form of a software product, which may be stored on a computer-readable storage medium such as ROM / RAM, magnetic disk, or optical disk, and may include several instructions for causing a computer device (e.g., a personal computer, server, or network device) to perform the methods described in each embodiment or parts thereof.

[0087] Finally, it should be noted that the embodiments described above are merely for illustrating, and not limiting, the technical means of the present invention. Although the present invention has been described in detail with reference to the embodiments described above, it should be understood by those skilled in the art that it is still possible to modify the technical means described in each of the embodiments above, or to replace some of the technical features with equivalent ones. Such modifications or replacements will not cause the essence of the corresponding technical means to deviate from the spirit and scope of the technical means of each embodiment of the present invention.

Claims

1. A wafer alignment method applied to a main controller, To acquire multiple first sampling data of the wafer edge as the wafer rotates once, Based on the plurality of first sampling data, a second sampling data of the wafer notch is determined, Based on the second sampling data, the wafer center position and wafer notch position are determined, A wafer alignment method characterized by comprising controlling a drive motor based on the wafer notch position and the wafer center position to perform positional alignment with respect to the wafer.

2. Determining the second sampling data of the wafer notch based on the plurality of first sampling data described above is: Perform differential calculations on each of the first sample data points to obtain multiple derivative values. Determining the outlier among the aforementioned multiple differential values, The features include determining the first sampling data for calculating the outliers as the second sampling data of the wafer notch. The wafer alignment method according to claim 1.

3. The wafer is driven and rotated by a vacuum suction cup, and each of the first sampling data includes the length and angle of the sampling point relative to the center of the vacuum suction cup. The differential calculation performed on each of the first sampling data is calculated using the following formula: [Math 1] Here, n represents the nth sampling point, g(n) represents the derivative 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-1)th sampling point, a(n) represents the angle corresponding to the nth sampling point, and a(n-1) represents the angle corresponding to the (n-1)th sampling point. The wafer alignment method according to claim 2.

4. Determining the wafer center position based on the second sampling data is: The process involves removing the second sampling data from the plurality of first sampling data to obtain the remaining sampling data. The remaining sampled data is converted into a first Cartesian coordinate system, wherein the first Cartesian coordinate system is a Cartesian coordinate system with the center of the vacuum suction cup as the origin. Based on the first Cartesian coordinate system, a single circle is obtained by fitting, The process is characterized by including determining the center of the circle as the wafer center and determining the coordinates of the center as the wafer center position. The wafer alignment method according to claim 3.

5. Determining the wafer notch position based on the second sampling data is: Converting the second sampling data into a second Cartesian coordinate system in the first Cartesian coordinate system, The method involves subtracting the coordinates of the center of the wafer from the second set of Cartesian coordinates to obtain the third set of Cartesian coordinates in the second set of Cartesian coordinates of the second set of sampled data, wherein the second set of Cartesian coordinates is a set of Cartesian coordinates with the center of the wafer as the origin. Convert the third Cartesian coordinates to polar coordinates and obtain the corrected second sampling data, Based on the corrected second sampling data, a quadratic curve is obtained by fitting, The minimum point of the quadratic curve is determined as the lowest point of the wafer notch, The method is characterized by determining the wafer notch position based on the angle of the lowest point of the wafer notch with respect to the wafer center. The wafer alignment method according to claim 4.

6. Based on the aforementioned wafer notch position and wafer center position, controlling the drive motor to perform position alignment with the wafer is: Based on the wafer notch position and angle correction value, the drive motor is controlled to rotate the wafer notch to a preset angle. The method is characterized by controlling a drive motor based on the wafer center position to move the wafer center to a preset position. The wafer alignment method according to claim 5.

7. The angle correction value is determined by the following method: Based on the wafer's center position, the coordinates of the lowest point, and the vacuum suction cup's center position, a triangle is constructed. The method is characterized by calculating the angle of the lowest point relative to the center of the vacuum suction cup based on the side lengths of the three sides of the triangle, and obtaining an angle correction value. The wafer alignment method according to claim 6.

8. An acquisition module configured to acquire multiple first sampling data of the wafer edge as the wafer rotates once, A wafer notch data determination module is configured to determine second sampling data of a wafer notch based on the plurality of first sampling data, A position determination module configured to determine the wafer center position and wafer notch position based on the second sampling data, A main controller comprising a control alignment module configured to control a drive motor to perform position alignment with respect to the wafer based on the wafer notch position and the wafer center position.

9. An electronic device comprising memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it realizes the steps in the wafer alignment method described in any one of claims 1 to 7.

10. A non-temporary computer-readable storage medium in which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps in the wafer alignment method described in any one of claims 1 to 7 are realized.

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