Wafer positioning method and system, chemical mechanical polishing equipment and storage medium

Abstract

The invention provides a wafer positioning method and system and chemical mechanical polishing equipment. The wafer positioning method comprises the following steps: acquiring distance data from a plurality of positions of the edge of a wafer to the rotation center of the motion platform through a linear sensor; analyzing the distance data to extract edge region data and gap region data; determining the offset of the centroid of the wafer relative to the rotation center of the motion table according to the edge area data; analyzing the notch area data to determine a first deflection angle of the notch orientation of the wafer and a preset translation direction of the motion table; and determining a corresponding positioning compensation amount according to the offset, the first deflection angle and a second deflection angle between the linear sensor and the preset translation direction of the motion table, and compensating a measurement coordinate of the measurement point in the motion table coordinate system by using the corresponding positioning compensation amount, and determining the real coordinate of the measurement point in the motion table coordinate system.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer positioning method, a wafer positioning system, a chemical mechanical polishing device, and a computer-readable storage medium. Background Art

[0002] Chemical Mechanical Planarization (CMP) equipment is one of the key process equipment in semiconductor manufacturing. With the development of chip manufacturing technology, the utilization rate of chemical mechanical polishing process in the integrated circuit manufacturing process has increased rapidly, so the performance requirements for chemical mechanical polishing equipment are also increasing. However, the existing chemical mechanical polishing equipment usually does not have the function of film thickness measurement, so it is necessary to configure a mounted film thickness measurement machine to measure the film thickness to characterize the polishing thickness and / or polishing flatness of the chemical mechanical polishing process. However, since the measurement accuracy of the film thickness measurement machine is closely related to the wafer positioning accuracy, the wafer positioning of the traditional measurement equipment depends on the pre-calibration module in the equipment front end module (EFEM), and the positioning direction of the wafer is closely related to the installation position of the positioning sensor. Due to the presence of certain mechanical errors in the pre-calibration module, the result of wafer positioning contains an unknown error angle, which affects the accuracy of wafer positioning. In addition, this positioning method requires multiple placement and calculation of the wafer during the positioning process, which is inefficient.

[0003] In order to overcome the above-mentioned defects in the prior art, an improved wafer positioning method is urgently needed in the art to improve the efficiency of wafer measurement and the accuracy of wafer positioning in the chemical mechanical polishing process. Summary of the invention

[0004] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or decisive elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0005] In order to overcome the above-mentioned defects in the prior art, the present invention provides a wafer positioning method, a wafer positioning system, a chemical mechanical polishing device and a computer-readable storage medium, which can not only determine the offset and a first deflection angle of the wafer relative to the moving table based on multiple marks on a standard wafer, but also determine the second deflection angle of the linear sensor and the preset translation direction of the moving table, so as to more efficiently and accurately compensate the coordinates of the measuring point in the moving table coordinate system, so as to improve the efficiency of wafer measurement and the accuracy of wafer positioning.

[0006] Specifically, the wafer positioning method provided in accordance with the first aspect of the present invention comprises the following steps: placing a wafer to be positioned on a moving table, and rotating the moving table to collect distance data from multiple positions of the wafer edge to the rotation center of the moving table via a linear sensor; analyzing the distance data from the multiple positions to the rotation center of the moving table to extract edge area data and notch area data therefrom; and determining an offset (X) of the centroid of the wafer relative to the rotation center of the moving table based on the edge area data. 0 ,Y 0 ); Analyze the gap area data to determine its center point coordinates (X 1 ,Y 1 ), and combined with the offset (X 0 ,Y 0 ), to determine the first deflection angle θ of the notch of the wafer and the preset translation direction of the moving stage; according to the offset (X 0 ,Y 0 ), the first deflection angle θ, and the second deflection angle Δθ of the linear sensor and the preset translation direction of the motion stage, determine the corresponding positioning compensation amount (x′, y′); and use the positioning compensation amount (x′, y′) to compensate the measurement coordinates (x, y) of the measurement point in the motion stage coordinate system to determine the real coordinates (x′, y′) of the measurement point in the motion stage coordinate system. c ,y c ).

[0007] Furthermore, in some embodiments of the present invention, before collecting distance data from multiple positions of the edge of the wafer to the rotation center of the moving stage, the wafer positioning method also includes the following steps: adsorbing a standard wafer to the moving stage, wherein the center of the detection surface of the standard wafer has a first mark; moving the moving stage to move the center of the first mark to the rotation center of the moving stage, and rotating the moving stage to collect the induced voltage at multiple positions of the edge of the standard wafer via the linear sensor; and according to the distance R from the edge area of ​​the standard wafer to its centroid, and the average value V of the induced voltage when the linear sensor collects each of the positions of the edge area. avr , calibrate the corresponding relationship between the induced voltage and the distance.

[0008] Further, in some embodiments of the present invention, the step of moving the motion stage to move the center of the first mark to the rotation center of the motion stage includes: initially moving the motion stage to move the first mark to a field of view of a camera, and rotating the motion stage according to a preset first step length to acquire a plurality of calibration images via the camera; parsing each of the calibration images to respectively determine the center coordinates (x i ,y i ); for each of the center coordinates (x i ,y i ) to perform fitting to determine the rotation center coordinates of the rotation center of the motion stage in the camera coordinate system; and according to the rotation center coordinates, move the motion stage again to move the center of the first marker to the rotation center of the motion stage.

[0009] Furthermore, in some embodiments of the present invention, the first step length is not greater than 360 / m°, the number of calibration images collected is not less than m, and the center coordinates (x i ,y i ) to determine the rotation center coordinates of the rotation center of the motion platform in the camera coordinate system, comprising: constructing a least squares fitting equation group about the rotation center coordinates:

[0010]

[0011] Wherein, A and B indicate the offset of the rotation center coordinates; C indicates the radius of the circle corresponding to the rotation center coordinates; and the center coordinates (x i ,y i ), substitute into the least squares fitting equation group to determine the rotation center coordinates of the rotation center of the motion platform in the camera coordinate system

[0012] Further, in some embodiments of the present invention, the step of rotating the moving stage to collect distance data from multiple positions of the wafer edge to the rotation center of the moving stage includes: rotating the moving stage according to a preset second step length to obtain the induced voltage when the linear sensor collects n positions of the wafer edge. The second step length is not greater than 0.2°. n is a natural number not less than 1800; and substituting the induced voltage when the linear sensor collects each of the positions of the wafer edge into the corresponding relationship between the induced voltage and the distance to determine the distance data from each of the positions of the wafer edge to the rotation center of the moving stage.

[0013] Further, in some embodiments of the present invention, the length of the linear sensor along the radial direction of the wafer is L. The step of substituting the induced voltage when the linear sensor collects each of the positions of the wafer edge into the corresponding relationship between the induced voltage and the distance to determine the distance data from each of the positions of the wafer edge to the rotation center of the moving stage comprises: according to the induced voltage V obtained by the linear sensor when collecting each of the positions of the wafer edge 1 ~V n , determine the minimum value V min and maximum value V max ; and each of the induced voltages V 1 ~V n Substitute into the following conversion formulas respectively:

[0014]

[0015] To determine the distance R from each position of the wafer edge to the rotation center of the motion stage 1 ~R n .

[0016] Further, in some embodiments of the present invention, the step of parsing the distance data from the plurality of positions to the rotation center of the motion stage to extract the edge area data and the gap area data therein comprises: calculating the distance R from the plurality of positions on the edge of the wafer to the rotation center of the motion stage; 1 ~R n , perform differential operations on adjacent positions to determine a differential array (Diff 1 ,Diff 2 ,…,Diff n ),in, Determine a division threshold according to the standard deviation of each element in the difference array; traverse the difference array to determine the starting point and the end point of the notch area at the edge of the wafer according to the division threshold; and calculate the distance R from the starting point, the end point and each position between the two to the rotation center of the motion stage. start ~R end , determine the gap area data; and according to the distance R from each position outside the gap area to the rotation center of the motion table 1 ~R start-1 and R end+1 ~R n , determine the edge area data.

[0017] Furthermore, in some embodiments of the present invention, the step of traversing the difference array to determine the starting point and the end point of the notch area at the edge of the wafer according to the partition threshold comprises: traversing the difference array and comparing the value of each element therein with the partition threshold; responding to the value Diff of any of the elements start is greater than the division threshold, and the values ​​of the preset number of elements before it are all less than the division threshold, the position corresponding to the element is determined as the starting point of the gap area; and in response to the value Diff of any of the elements end If the value of a preset number of elements is greater than the division threshold, and the values ​​of the elements thereafter are all less than the division threshold, the position corresponding to the element is determined as the end point of the gap area.

[0018] Further, in some embodiments of the present invention, the data of the gap region is analyzed to determine the coordinates (X 1 ,Y 1 ) comprises: according to the distance R from each position in the edge area to the rotation center of the motion platform start ~R end , and the corresponding rotation angle of the motion stage, determine the X-axis projection x of each position in the edge region in the motion stage coordinate system start ~x end and the Y-axis projection y start ~y end According to the X-axis projection x start ~x end Construct the independent variable array and project the amount y on the Y axis start ~y end Construct the dependent variable array to generate the following system of linear equations:

[0019]

[0020] Wherein, m is the amount of data in the edge region. i and j are the powers of the independent variables in the linear equation system.ij and G im is an element in the coefficient matrix of the linear equation group; and the linear equation group is solved by Gaussian elimination method to calculate the parameters of the corresponding quadratic fitting curve, so as to determine the center point coordinate (X 1 ,Y 1 ).

[0021] Further, in some embodiments of the present invention, the offset (X) of the centroid of the wafer relative to the rotation center of the motion stage is determined based on the edge area data. 0 ,Y 0 The step of ) comprises: randomly selecting three positions from the edge area data, and determining the center coordinates (x ) of a circle formed by the three positions in the motion stage coordinate system according to the distances from the three positions to the rotation center of the motion stage and the corresponding rotation angle of the motion stage. 0 ,y 0 ); and the center coordinates (x 0 ,y 0 ) is the initial position parameter P 0 , construct an iterative optimization function of the LM algorithm, and calculate the optimal solution of the iterative optimization according to the chi-square value of the center coordinates before and after the iterative optimization to determine the offset (X 0 ,Y 0 ).

[0022] Further, in some embodiments of the present invention, the iterative optimization function is expressed as:

[0023]

[0024] Among them, P k and P k+1 are the position parameters obtained at the kth and k+1th iterations respectively. k is the Jacobian matrix formed by calculating the partial derivatives of the residual value with respect to the location parameters. λ is the damping coefficient that adjusts the iteration speed. I is the identity matrix.

[0025] The calculation formula of the chi-square value is:

[0026]

[0027] Wherein, Chisq is the chi-square value, n is the number of positions where the linear sensor collects the edge of the wafer, k is a natural number, (x k+1 ,y k+1 ) is the position parameter P k+1 The coordinates of P k+1 is the position parameter P k+1The radius is represented by .

[0028] Further, in some embodiments of the present invention, the optimal solution of the iterative optimization is calculated according to the chi-square value of the center coordinates before and after the iterative optimization to determine the offset (X 0 ,Y 0 ) includes: the chi-square value Chisq k+1 The chi-square value Chisq after the previous iteration k Compare; in response to the chi-square value Chisq after this round of iteration k+1 Less than the chi-square value Chisq after the previous iteration k , reduce the damping coefficient to perform the next round of iterative optimization; in response to the chi-square value Chisq after this round of iteration k+1 Greater than or equal to the chi-square value Chisq after the previous iteration k , increase the damping coefficient to perform the next round of iterative optimization; and respond to the chi-square value Chisq after this round of iteration k+1 is smaller than the preset chi-square threshold, according to the position parameter P obtained in this round of iteration k+1 , determine the offset (X) of the center of shape of the wafer relative to the rotation center of the motion stage 0 ,Y 0 ).

[0029] Furthermore, in some embodiments of the present invention, a second mark is made on the edge of the standard wafer. The second mark is located on the extension line connecting the center of the notch of the standard wafer and the first mark. Before collecting the distance data from multiple positions of the edge of the wafer to the rotation center of the motion stage, the wafer positioning method further includes the following steps: after moving the center of the first mark to the rotation center of the motion stage, rotating the motion stage for the first time to move the second mark to the center of the camera field of view, and recording the rotation angle θ of the motion stage at this time. 0 ; Rotate the motion stage again to collect distance data from multiple positions of the edge of the standard wafer to the rotation center of the motion stage via the linear sensor, and analyze the distance data to determine the deflection angle θ of the notch of the standard wafer relative to the preset translation direction of the motion stage 1 ; and according to the rotation angle θ 0 and the deflection angle θ 1 , determine a second deflection angle Δθ between the linear sensor and a preset translation direction of the motion platform.

[0030] Further, in some embodiments of the present invention, the first deflection angle θ is expressed as:

[0031]

[0032] The positioning compensation (x′, y′) is expressed as:

[0033]

[0034] The real coordinate (x c ,y c ) is represented as:

[0035] x c =x+x′

[0036] y c =y+y′.

[0037] In addition, the wafer positioning system provided according to the second aspect of the present invention includes a memory and a processor. The memory stores computer instructions. The processor is connected to the memory and is used to execute the computer instructions stored in the memory to implement the wafer positioning method provided by the first aspect of the present invention.

[0038] In addition, the chemical mechanical polishing equipment provided according to the third aspect of the present invention includes a polishing mechanism, a film thickness measuring machine and a wafer positioning system as provided in the second aspect of the present invention. The polishing mechanism is used to perform a chemical mechanical polishing process on a wafer to be processed. The film thickness measuring machine is used to determine the film thickness at multiple measuring points on the surface of the wafer. The wafer positioning system is used to determine the real coordinates of each of the measuring points to cooperate with the film thickness measuring machine to characterize the polishing thickness and / or polishing flatness of the chemical mechanical polishing process.

[0039] In addition, the computer-readable storage medium provided in the fourth aspect of the present invention stores computer instructions, which, when executed by a processor, implement the wafer positioning method provided in the first aspect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0041] Figure 1 A schematic flow chart of a wafer positioning method provided according to some embodiments of the present invention is shown.

[0042] Figure 2 A schematic diagram showing a wafer placed on a moving table according to some embodiments of the present invention is shown.

[0043] Figure 3A schematic diagram of a first marker provided according to some embodiments of the present invention is shown.

[0044] Figure 4 A schematic diagram showing movement of a first marker to the rotation center of a moving stage according to some embodiments of the present invention is shown.

[0045] Figure 5 A schematic diagram of collecting multiple positions of a wafer edge according to some embodiments of the present invention is shown.

[0046] Figure 6 A schematic diagram showing the principle of determining the offset of the centroid of a wafer relative to the rotation center of a motion stage according to some embodiments of the present invention is shown.

[0047] Figure 7 A schematic diagram of a second marker provided according to some embodiments of the present invention is shown.

[0048] Figure 8 A schematic diagram showing movement of a second marker to the center of a camera field of view according to some embodiments of the present invention is shown.

[0049] Fig. 9 A schematic diagram showing the principle of compensating wafer positioning based on a second mark according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0050] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0053] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0054] As mentioned above, existing chemical mechanical polishing equipment usually does not have the function of film thickness measurement, so it is necessary to configure a mounted film thickness measuring machine to measure the film thickness in order to characterize the polishing thickness and / or polishing flatness of the chemical mechanical polishing process. However, since the measurement accuracy of the film thickness measuring machine is closely related to the wafer positioning accuracy, the wafer positioning of traditional measuring equipment depends on the pre-calibration module in the equipment front end module (EFEM, Equipment Front End Module), and the positioning direction of the wafer is closely related to the installation position of the positioning sensor. Due to the presence of certain mechanical errors in the pre-calibration module, the result of wafer positioning contains an unknown error angle, which affects the accuracy of wafer positioning. In addition, this positioning method requires multiple placement and calculation of the wafer during the positioning process, which is inefficient.

[0055] In order to overcome the above-mentioned defects in the prior art, the present invention provides a wafer positioning method, a wafer positioning system, a chemical mechanical polishing device and a computer-readable storage medium, which can not only determine the offset and a first deflection angle of the wafer relative to the moving table based on multiple marks on a standard wafer, but also determine the second deflection angle of the linear sensor and the preset translation direction of the moving table, so as to more efficiently and accurately compensate the coordinates of the measuring point in the moving table coordinate system, so as to improve the efficiency of wafer measurement and the accuracy of wafer positioning.

[0056] In some non-limiting embodiments, the wafer positioning system provided in the second aspect of the present invention can be configured in the chemical mechanical polishing equipment provided in the third aspect of the present invention for implementation. Specifically, the chemical mechanical polishing equipment includes a polishing mechanism, a film thickness measuring machine and the wafer positioning system provided in the second aspect of the present invention. Here, the polishing mechanism is used to implement a chemical mechanical polishing process on the wafer to be processed. The film thickness measuring machine is used to determine the film thickness at multiple measuring points on the wafer surface. The wafer positioning system is used to determine the real coordinates of each measuring point, so as to cooperate with the film thickness measuring machine to characterize the polishing thickness and / or polishing flatness of the chemical mechanical polishing process.

[0057] In addition, in some optional embodiments, those skilled in the art may also integrate the wafer positioning system provided by the second aspect of the present invention into a film thickness measurement machine to meet the film thickness measurement requirements of other equipment.

[0058] Furthermore, the wafer positioning system provided in the second aspect of the present invention includes a memory and a processor. Here, the memory includes but is not limited to the computer-readable storage medium provided in the third aspect, on which computer instructions are stored. The processor is connected to the memory and is configured to execute the computer instructions stored in the memory to implement the wafer positioning method provided in the first aspect of the present invention.

[0059] The working principle of the above-mentioned wafer positioning system will be described below in conjunction with some embodiments of the wafer positioning method. Those skilled in the art will understand that these embodiments of the wafer positioning method are only some non-limiting implementation methods provided by the present invention, which are intended to clearly demonstrate the main concept of the present invention and provide some specific solutions that are convenient for the public to implement, rather than limiting all functions or all working methods of the wafer positioning system. Similarly, the wafer positioning system is also only a non-limiting implementation method provided by the present invention, and does not constitute a limitation on the execution subject and execution order of each step in these wafer positioning methods.

[0060] Please refer to Figure 1 and Figure 2 . Figure 1 A schematic flow chart of a wafer positioning method provided according to some embodiments of the present invention is shown. Figure 2 A schematic diagram showing a wafer placed on a moving table according to some embodiments of the present invention is shown.

[0061] like Figure 1 and Figure 2 As shown, the wafer positioning system can first place the wafer 11 to be positioned on the moving stage 12, and rotate the moving stage 12 to collect distance data from multiple positions of the edge of the wafer 11 to the rotation center 13 of the moving stage.

[0062] Furthermore, if Figure 2 As shown, in the process of adsorbing the wafer 11 onto the moving stage 12, the wafer positioning system can place the wafer 11 in the four gradient columns of the moving stage 12, and the wafer 11 will slide onto the wafer carrier through the columns. Afterwards, the wafer positioning system can control the moving stage 12 to vacuum adsorb the wafer 11, so as to use the column structure to preliminarily control the circumferential error of the wafer 11 on the moving stage 12.

[0063] Please refer to Figure 3 and Figure 4 . Figure 3 A schematic diagram of a first marker provided according to some embodiments of the present invention is shown. Figure 4 A schematic diagram showing movement of a first marker to the rotation center of a moving stage according to some embodiments of the present invention is shown.

[0064] In addition, in some preferred embodiments, before collecting the above-mentioned distance data, the wafer positioning system can first use a standard wafer with a first mark on the surface to calibrate the correspondence between the induced voltage when the linear sensor 14 collects multiple positions of the edge of the standard wafer and the distance from the edge area to its centroid.

[0065] Specifically, the wafer positioning system can firstly adsorb a standard wafer with a first mark made in the center of the detection surface to the moving stage 12. Here, the first mark is a specific standardized graphic structure made on the surface of the standard wafer by photolithography and other processes, including but not limited to geometric shapes such as lines, squares, and holes, and the size, shape, spacing and other parameters of these graphics can be made according to pre-set standards.

[0066] Further, in Figure 3 In the illustrated embodiment, the first mark is a four-leaf clover pattern.

[0067] Afterwards, if Figure 4 As shown, the wafer positioning system can move the moving stage 12 to move the center of the first mark to the rotation center 13 of the moving stage, and rotate the moving stage 12 to collect the induced voltage at multiple positions of the edge of the standard wafer via a CCD (Charge Coupled Device) linear sensor 14 and a high-speed I / O digital acquisition card.

[0068] Furthermore, in the process of moving the center of the first mark to the rotation center 13 of the moving stage, the wafer positioning system can first move the moving stage 12 for the first time to move the first mark to the field of view of a camera (not shown), and rotate the moving stage 12 according to a preset first step length to capture multiple calibration images.

[0069] Afterwards, the processor of the wafer positioning system can analyze each calibration image to determine the center coordinate (x i ,y i ).

[0070] After that, the processor can calculate the center coordinates (x i ,y i ) is fitted to determine the rotation center coordinates of the rotation center 13 of the motion stage in the camera coordinate system, and according to the rotation center coordinates, the motion stage 12 is moved again to move the center of the first mark to the rotation center 13 of the motion stage.

[0071] Furthermore, in some embodiments, the first step length is no greater than 360 / m°, and the number of calibration images collected is no less than m. For example, when m=12, the processor can construct the least squares fitting equation group about the rotation center coordinates as follows:

[0072]

[0073] Wherein, A and B indicate the offset of the rotation center coordinates, and C indicates the radius of the circle corresponding to the rotation center coordinates.

[0074] Afterwards, the processor can calculate the center coordinates (x i ,y i ), substitute into the least squares fitting equation group to determine the rotation center coordinates of the motion platform's rotation center 13 in the camera coordinate system

[0075] Then, the processor can calculate the average value V of the induced voltage at each position of the edge area according to the distance R from the edge area of ​​the standard wafer to its centroid and the linear sensor 14. avr , calibrate the corresponding relationship between induced voltage and distance.

[0076] Please refer to Figure 5 . Figure 5 A schematic diagram of collecting multiple positions of a wafer edge according to some embodiments of the present invention is shown.

[0077] After that, if Figure 5 As shown, in the process of collecting distance data from multiple positions on the edge of the wafer 11 to the rotation center 13 of the moving stage, the wafer positioning system can rotate the moving stage 12 according to a preset second step length to obtain the induced voltage when collecting n positions on the edge of the wafer 11 via the linear sensor 14 and the high-speed I / O digital acquisition card. Here, the second step length is not greater than 0.2° (for example: 0.18°), and n is a natural number not less than 1800 (for example: 2000).

[0078] Thereafter, the processor of the wafer positioning system can collect the induced voltage at each position of the edge of the wafer 11 by the linear sensor 14 and substitute it into the corresponding relationship between the induced voltage and the distance to determine the distance data from each position of the edge of the wafer 11 to the rotation center 13 of the moving table.

[0079] Further, in Figure 2 and Figure 5 In the embodiment shown, the length of the linear sensor 14 along the radial direction of the wafer 11 is L. Here, the processor can obtain the induced voltage V obtained by the linear sensor 14 when collecting various positions of the edge of the wafer 11. 1 ~V n , determine the minimum value V min and maximum value V max .

[0080] Afterwards, the processor can convert each sensed voltage V 1 ~V n Substitute into the following conversion formulas respectively:

[0081]

[0082] To determine the distance R from each position of the edge of the wafer 11 to the rotation center of the motion stage 1 ~R n .

[0083] Afterwards, the processor may parse the distance data from the above-mentioned multiple positions to the rotation center 13 of the moving table to extract the edge area data and the gap area data therein.

[0084] Specifically, the processor can calculate the distance R from multiple positions on the edge of the wafer 11 to the rotation center 13 of the motion stage. 1 ~R n , perform differential operations on adjacent positions to determine a differential array (Diff 1 ,Diff 2 ,…,Diff n ). Here,

[0085] Afterwards, the processor may determine a division threshold (eg, 3σ) according to the standard deviation of each element in the difference array.

[0086] Thereafter, the processor may traverse the differential array to determine the start and end points of the notch area at the edge of the wafer 11 according to the above-mentioned division threshold.

[0087] Specifically, the processor may compare the value of each element in the difference array with the above-mentioned partitioning threshold value during the process of traversing the difference array.

[0088] Afterwards, in response to the value Diff of any elementstart If the value of a preset number (for example, 3) of elements is greater than the division threshold, and the values ​​of the elements are all less than the division threshold, the processor can determine the position corresponding to the element as the starting point of the gap area.

[0089] Or, in response to the value Diff of any element end If the value of a preset number (eg, 3) of elements is greater than the division threshold, and the values ​​of the elements thereafter are all less than the division threshold, the processor may determine the position corresponding to the element as the end point of the gap area.

[0090] Then, the processor can calculate the distance R from the starting point, the end point and each position between the two to the rotation center 13 of the motion platform. start ~R end , determine the gap area data, and according to the distance R from each position outside the gap area to the rotation center 13 of the motion table 1 ~R start-1 and R end+1 ~R n , determine the edge area data.

[0091] Please refer to Figure 6 . Figure 6 A schematic diagram showing the principle of determining the offset of the centroid of a wafer relative to the rotation center of a motion stage according to some embodiments of the present invention is shown.

[0092] After that, if Figure 6 As shown, the processor can determine the offset (X) of the centroid 111 of the wafer 11 relative to the rotation center 13 of the moving stage according to the edge area data. 0 ,Y 0 ).

[0093] Specifically, the processor can select three locations (x 1 ,y 1 )、(x 2 ,y 2 )、(x 3 ,y 3 ), and according to the distance from the rotation center 13 of the motion stage and the corresponding rotation angle of the motion stage 12, the center coordinates (x 0 ,y 0 ):

[0094]

[0095] in,

[0096] Afterwards, the processor can also calculate the radius r of the wafer:

[0097]

[0098] After that, the processor can use the coordinates of the center of the circle (x 0 ,y 0 ) is the initial position parameter P 0 , construct the iterative optimization function of the LM algorithm, and calculate the optimal solution of the iterative optimization according to the chi-square value of the center coordinates before and after the iterative optimization to determine the offset (X 0 ,Y 0 ).

[0099] Further, in some embodiments, the above iterative optimization function is expressed as:

[0100]

[0101] Among them, P k and P k+1 are the position parameters obtained at the kth and k+1th iterations, respectively. λ is the damping coefficient for adjusting the iteration speed, and I is the unit matrix. J k It is the Jacobian matrix formed by calculating the partial derivatives of the residual value with respect to the location parameter. Here, it means using the central difference method to find the partial derivatives:

[0102]

[0103] Among them, f is the residual calculation function, and h is the change step size of the position parameter P.

[0104] In addition, in some embodiments, the calculation formula of the chi-square value is:

[0105]

[0106] Where Chisq is the chi-square value, n is the number of locations where the linear sensor collects the edge of the wafer, k is a natural number, (x k+1 ,y k+1 ) is the position parameter P k+1 The coordinates of R k+1 is the position parameter P k+1 The radius is represented by .

[0107] Furthermore, when iteratively determining the offset (X) of the centroid 111 of the wafer 11 relative to the rotation center 13 of the motion stage, 0 ,Y 0 ), the wafer positioning system can calculate the chi-square value Chisq after this round of iteration. k+1 The chi-square value Chisq after the previous iteration k Make a comparison.

[0108] Afterwards, in response to the chi-square value Chisq after this round of iteration k+1 Less than the chi-square value Chisq after the previous iteration k , the processor can determine that this round of iteration is effective, thereby reducing the damping coefficient (for example: λ=0.1*λ) to perform the next round of iterative optimization.

[0109] Or, in response to the chi-square value Chisq after this round of iteration k+1 Greater than or equal to the chi-square value Chisq after the previous iteration k , the processor may determine that the current round of iteration is invalid, and thus increase the damping coefficient (eg, λ=10*λ) to perform the next round of iterative optimization.

[0110] Or, in response to the chi-square value Chisq after this round of iteration k+1 Less than the preset chi-square threshold (for example: 10 -7 ), the processor can determine that the optimal solution has been found, and thus the position parameter P obtained in this round of iteration k+1 , determine the offset (X) of the centroid 111 of the wafer 11 relative to the rotation center 13 of the motion stage 0 ,Y 0 ).

[0111] After that, if Figure 6 As shown, the processor can parse the gap area data to determine the coordinates (X 1 ,Y 1 ).

[0112] Specifically, the processor can calculate the distance R between each position in the edge area and the rotation center 13 of the motion stage. start ~R end , and the corresponding rotation angle of the motion stage 12, determine the X-axis projection x of each position in the edge area in the motion stage coordinate system start ~x end and the Y-axis projection y start ~y end .

[0113] The processor can then project the amount x along the x-axis start ~x end Construct the independent variable array and project the amount y along the Y axis start ~y end Construct the dependent variable array to generate the following system of linear equations:

[0114]

[0115] Where m is the amount of data in the edge region, i and j are the powers of the independent variables in the linear equation system, and G ij and G imare the elements in the coefficient matrix of the linear system.

[0116] Afterwards, the wafer positioning system can solve the linear equations using Gaussian elimination method to calculate the parameters of the corresponding quadratic fitting curve, so as to determine the coordinates (X 1 ,Y 1 ).

[0117] Afterwards, the wafer positioning system can calculate the center point coordinates (X 1 ,Y 1 ), and combined with the offset (X 0 ,Y 0 ) to determine that the notch of the wafer is oriented toward a first deflection angle θ in a preset translation direction of the moving stage 12.

[0118] Please refer to Figure 7 to Figure 9 . Figure 7 A schematic diagram of a second marker provided according to some embodiments of the present invention is shown. Figure 8 A schematic diagram showing movement of a second marker to the center of a camera field of view according to some embodiments of the present invention is shown. Fig. 9 A schematic diagram showing the principle of compensating wafer positioning based on a second mark according to some embodiments of the present invention is shown.

[0119] In addition, Figure 7 In the illustrated embodiment, a second mark is also made on the edge of the standard wafer. The second mark is located on the extension line connecting the notch center 112 of the standard wafer and the first mark.

[0120] like Figure 7 and Figure 8 As shown, before collecting the distance data, the wafer positioning system may also rotate the motion stage 12 for the first time after moving the center of the first mark to the rotation center of the motion stage 12 to move the second mark to the center of the camera field of view area 81, and record the rotation angle θ of the motion stage 12 at this time. 0 .

[0121] Afterwards, the wafer positioning system can rotate the motion stage 12 again to collect distance data from multiple positions of the edge of the standard wafer to the rotation center 13 of the motion stage, and analyze the distance data to determine the deflection angle θ of the notch of the standard wafer relative to the preset translation direction of the motion stage 12. 1 .

[0122] After that, if Fig. 9 As shown, the wafer positioning system can be adjusted according to the rotation angle θ 0 and the deflection angle θ 1 , determine the second deflection angle Δθ=θ between the linear sensor 14 and the preset translation direction of the motion stage 120 +θ 1 .

[0123] Then, the wafer positioning system can adjust the wafer positioning system according to the offset (X) of the wafer centroid 111 relative to the rotation center 13 of the motion stage. 0 ,Y 0 ), a first deflection angle θ between the notch of the wafer 11 and the preset translation direction of the moving stage 12, and a second deflection angle Δθ between the linear sensor 14 and the preset translation direction of the moving stage 12, determine the corresponding positioning compensation amount (x′, y′):

[0124]

[0125] The first deflection angle θ between the notch of the wafer 11 and the preset translation direction of the moving stage 12 is expressed as

[0126] During wafer measurement, the processor can use the positioning compensation (x′, y′) to compensate the measurement coordinates (x, y) of the measurement point in the motion stage coordinate system to determine the actual coordinates (x, y) of the measurement point in the motion stage coordinate system. c ,y c ):

[0127] x c =x+x′

[0128] y c =y+y′

[0129] In this way, the above-mentioned wafer positioning method provided in the first aspect of the present invention can again compensate the measurement coordinates of the measurement point based on the second mark to compensate for the second deflection angle Δθ in the preset translation direction of the linear sensor 14 and the moving stage 12 caused by mechanical errors, thereby avoiding it affecting the accuracy of subsequent wafer positioning.

[0130] In addition, those skilled in the art have measured the wafer positioning accuracy without the above correction step, and the error is 100um. After the above wafer positioning method provided by the first aspect of the present invention is corrected, the error of wafer positioning can be controlled within 8um, which greatly improves the accuracy of wafer positioning.

[0131] In summary, the above-mentioned wafer positioning method, wafer positioning system, chemical mechanical polishing equipment and computer-readable storage medium provided by the present invention can determine the offset and the first deflection angle of the wafer relative to the moving table based on multiple marks on the standard wafer, and can also determine the second deflection angle of the preset translation direction of the linear sensor 14 and the moving table 12, so as to more efficiently and accurately compensate the coordinates of the measurement point in the moving table coordinate system, so as to improve the efficiency of wafer measurement and the accuracy of wafer positioning.

[0132] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0133] Those skilled in the art will appreciate that information, signals, and data may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips cited throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0134] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. The technician may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of the present invention.

[0135] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration.

[0136] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0137] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as a computer program product in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, a server, or other remote source using a coaxial cable, a fiber optic cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disk often reproduces data magnetically, while disc reproduces data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0138] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wafer positioning method, characterized in that: The following steps are involved: Placing a wafer to be positioned on a moving stage, and rotating the moving stage to collect distance data from multiple positions of the edge of the wafer to the rotation center of the moving stage via a linear sensor; Parsing the distance data from the plurality of positions to the rotation center of the motion platform to extract edge area data and gap area data therefrom; Determine, based on the edge area data, an offset (X0, Y0) of the centroid of the wafer relative to the rotation center of the motion stage; Parsing the notch area data to determine the center point coordinates (X1, Y1), and combining the offset (X0, Y0) to determine a first deflection angle θ between the notch direction of the wafer and the preset translation direction of the motion stage; Determine a corresponding positioning compensation amount (x′, y′) according to the offset (X0, Y0), the first deflection angle θ, and a second deflection angle Δθ of a preset translation direction between the linear sensor and the motion stage; and The positioning compensation amount (x′, y′) is used to compensate the measurement coordinates (x, y) of the measurement point in the motion stage coordinate system to determine the real coordinates (x′, y′) of the measurement point in the motion stage coordinate system. c ,y c ).

2. The wafer positioning method according to claim 1, characterized in that: Before collecting distance data from multiple positions of the wafer edge to the rotation center of the motion stage, the wafer positioning method further includes the following steps: Adsorbing a standard wafer onto the moving stage, wherein a first mark is provided at the center of a detection surface of the standard wafer; Moving the moving stage to move the center of the first mark to the rotation center of the moving stage, and rotating the moving stage to collect induced voltages at multiple positions of the edge of the standard wafer via the linear sensor; and According to the distance R from the edge area of ​​the standard wafer to its centroid, and the average value V of the induced voltage when the linear sensor collects the positions of the edge area avr , calibrate the corresponding relationship between the induced voltage and the distance.

3. The wafer positioning method according to claim 2, characterized in that: The step of moving the motion stage to move the center of the first mark to the rotation center of the motion stage comprises: Initially moving the motion stage to move the first mark to a field of view of a camera, and rotating the motion stage by a preset first step length to acquire a plurality of calibration images via the camera; Analyze each calibration image to determine the center coordinates (x i ,y i ); For each of the center coordinates (x i ,y i ) to perform fitting to determine the rotation center coordinates of the rotation center of the motion platform in the camera coordinate system; and According to the rotation center coordinates, the motion stage is moved again to move the center of the first mark to the rotation center of the motion stage.

4. The wafer positioning method according to claim 3, characterized in that: The first step length is no greater than 360 / m°, the number of calibration images collected is no less than m, and the center coordinates (x i ,y i ) to determine the coordinates of the rotation center of the motion platform in the camera coordinate system, comprising: Construct the least squares fitting equation system about the rotation center coordinates: Wherein, A and B indicate the offset of the rotation center coordinate, and C indicates the radius of the circle corresponding to the rotation center coordinate; and The center coordinates (x i ,y i ), substitute into the least squares fitting equation group to determine the rotation center coordinates of the rotation center of the motion platform in the camera coordinate system 5. The wafer positioning method according to claim 2, characterized in that: The step of rotating the motion stage to collect distance data from multiple positions of the wafer edge to the rotation center of the motion stage includes: Rotating the moving stage according to a preset second step length to obtain the induced voltage when the linear sensor collects n positions of the wafer edge, wherein the second step length is not greater than 0.2°, and n is a natural number not less than 1800; and The induced voltage collected by the linear sensor at each position of the wafer edge is substituted into the corresponding relationship between the induced voltage and the distance to determine the distance data from each position of the wafer edge to the rotation center of the moving table.

6. The wafer positioning method according to claim 5, characterized in that: The length of the linear sensor along the radial direction of the wafer is L, and the steps of collecting the induced voltage at each position of the wafer edge by the linear sensor and substituting the induced voltage into the corresponding relationship between the induced voltage and the distance to determine the distance data from each position of the wafer edge to the rotation center of the moving stage include: According to the induced voltages V1 to V2 obtained by the linear sensor when collecting the positions of the wafer edge, n , determine the minimum value V min and maximum value V max ;as well as The induced voltages V1 to V n Substitute into the following conversion formulas respectively: To determine the distances R1 to R2 from each position of the wafer edge to the rotation center of the motion stage. n .

7. The wafer positioning method according to claim 1, characterized in that: The step of analyzing the distance data from the plurality of positions to the rotation center of the motion platform to extract edge area data and gap area data therefrom comprises: The distances R1 to R2 from the edge of the wafer to the rotation center of the moving table are measured. n , perform differential operations on adjacent positions to determine a differential array (Diff1, Diff2, ..., Diff n ),in, Determining a partition threshold according to the standard deviation of each element in the difference array; Traversing the difference array to determine the starting point and the end point of the notch area at the edge of the wafer according to the division threshold; According to the distance R from the starting point, the end point and each position between the two to the rotation center of the motion platform start ~R end , determine the gap area data; and According to the distances R1 to R2 from each position outside the notch area to the rotation center of the motion table, start-1 and R end+1 ~R n , determine the edge area data.

8. The wafer positioning method according to claim 7, characterized in that: The step of traversing the difference array to determine the starting point and the end point of the notch area at the edge of the wafer according to the division threshold comprises: Traversing the difference array, and comparing the value of each element therein with the partition threshold; In response to the value Diff of any of the elements start is greater than the division threshold, and the values ​​of the preset number of elements before it are all smaller than the division threshold, determining the position corresponding to the element as the starting point of the gap area; and In response to the value Diff of any of the elements end If the value of a preset number of elements is greater than the division threshold, and the values ​​of the elements thereafter are all less than the division threshold, the position corresponding to the element is determined as the end point of the gap area.

9. The wafer positioning method according to claim 7, characterized in that: The step of analyzing the gap area data to determine the center point coordinates (X1, Y1) thereof includes: According to the distance R between each position in the edge area and the rotation center of the motion platform start ~R end , and the corresponding rotation angle of the motion stage, determine the X-axis projection x of each position in the edge region in the motion stage coordinate system start ~x end and the Y-axis projection y start ~y end ; According to the X-axis projection amount x start ~x end Construct the independent variable array and project the amount y along the Y axis start ~y end Construct the dependent variable array to generate the following system of linear equations: Wherein, m is the amount of data in the edge region, i and j are the powers of the independent variables in the linear equation system, G ij and G im are the elements in the coefficient matrix of the linear equation system; and The linear equations are solved by using Gaussian elimination method to calculate the parameters of the corresponding quadratic fitting curve, so as to determine the coordinates (X1, Y1) of the center point of the notch area according to the minimum value of the quadratic fitting curve.

10. The wafer positioning method according to claim 1, characterized in that: The step of determining the offset (X0, Y0) of the centroid of the wafer relative to the rotation center of the motion stage according to the edge area data comprises: Randomly select three positions from the edge area data, and determine the center coordinates (x0, y0) of a circle formed by the three positions in the motion stage coordinate system according to their distances to the rotation center of the motion stage and the corresponding rotation angle of the motion stage; and Taking the center coordinates (x0, y0) as the initial position parameter P0, the iterative optimization function of the LM algorithm is constructed, and the optimal solution of the iterative optimization is calculated according to the chi-square value of the center coordinates before and after the iterative optimization to determine the offset (X0, Y0) of the centroid of the wafer relative to the rotation center of the motion stage.

11. The wafer positioning method according to claim 10, characterized in that: The iterative optimization function is expressed as: Among them, P k and P k+1 are the position parameters obtained at the kth and k+1th iterations, respectively, and J k is the Jacobian matrix formed by calculating the partial derivatives of the residual value with respect to the position parameter, λ is the damping coefficient for adjusting the iteration speed, I is the identity matrix, The calculation formula of the chi-square value is: Wherein, Chisq is the chi-square value, n is the number of positions where the linear sensor collects the edge of the wafer, k is a natural number, (x k+1 ,y k+1 ) is the position parameter P k+1 The coordinates of R k+1 is the position parameter P k+1 The radius is represented by .

12. The wafer positioning method according to claim 11, characterized in that: The step of calculating the optimal solution of iterative optimization according to the chi-square value of the center coordinates before and after iterative optimization to determine the offset (X0, Y0) of the center of shape of the wafer relative to the rotation center of the motion stage comprises: The chi-square value Chisq after this round of iteration k+1 The chi-square value Chisq after the previous iteration k Make comparisons; In response to the chi-square value Chisq after this round of iteration k+1 Less than the chi-square value Chisq after the previous iteration k , reducing the damping coefficient to carry out the next round of iterative optimization; In response to the chi-square value Chisq after this round of iteration k+1 Greater than or equal to the chi-square value Chisq after the previous iteration k , increasing the damping coefficient to perform the next round of iterative optimization; and In response to the chi-square value Chisq after this round of iteration k+1 is smaller than the preset chi-square threshold, according to the position parameter P obtained in this round of iteration k+1 , determine the offset (X0, Y0) of the centroid of the wafer relative to the rotation center of the motion stage.

13. The wafer positioning method according to claim 3, characterized in that: A second mark is also made on the edge of the standard wafer, and the second mark is located on the extension line connecting the center of the notch of the standard wafer and the first mark. Before collecting the distance data from multiple positions of the edge of the wafer to the rotation center of the motion stage, the wafer positioning method further includes the following steps: After the center of the first mark is moved to the rotation center of the motion stage, the motion stage is rotated for the first time to move the second mark to the center of the camera field of view, and the rotation angle θ0 of the motion stage at this time is recorded; Rotating the moving stage again to collect distance data from multiple positions of the edge of the standard wafer to the rotation center of the moving stage via the linear sensor, and analyzing the distance data to determine the deflection angle θ1 of the notch of the standard wafer relative to the preset translation direction of the moving stage; and According to the rotation angle θ0 and the deflection angle θ1, a second deflection angle Δθ in a preset translation direction between the linear sensor and the motion stage is determined.

14. The wafer positioning method according to claim 1, characterized in that: The first deflection angle θ is expressed as: The positioning compensation (x′, y′) is expressed as: The real coordinate (x c ,y c ) is represented as: x c =x+x′ and c =y+y′。 15. A wafer positioning system, characterized in that: include: a memory having computer instructions stored thereon; as well as A processor is connected to the memory and is used to execute computer instructions stored in the memory to implement the wafer positioning method according to any one of claims 1 to 14.

16. A chemical mechanical polishing device, characterized in that: include: A grinding mechanism, used for performing a chemical mechanical grinding process on the wafer to be processed; A film thickness measuring machine, used to determine the film thickness at multiple measuring points on the surface of the wafer; as well as The wafer positioning system as claimed in claim 15 is used to determine the real coordinates of each of the measurement points to cooperate with the film thickness measurement machine to characterize the polishing thickness and / or polishing flatness of the chemical mechanical polishing process.

17. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the wafer positioning method according to any one of claims 1 to 14 is implemented.

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