Method, system and storage medium for calibrating stitching error of stitched objective lens

Abstract

The present invention provides a method and system for calibrating the stitching error of stitched objective lenses, as well as a storage medium, which are applicable to the field of semiconductor device manufacturing. In an embodiment of the present invention, a first mark group on a mask is moved into the field of view of a first row of objective lenses, and the first row of mark groups are exposed at predetermined positions on a substrate. The substrate is then moved, and the predetermined positions exposed with the first mark group are moved into the field of view of a second row of objective lenses. The second mark group on the mask is exposed at predetermined positions on the substrate. Based on the actual positions of the marks in the first and second mark groups on the substrate, the stitching error between two adjacent objective lenses to be stitched together in the two rows of objective lenses is accurately obtained. The stitching error is then used to compensate and calibrate the two adjacent objective lenses to be stitched together, thereby improving the estimation accuracy of the stitching error of the objective lenses.

Description

Technical Field

[0001] The present invention relates to the field of photolithography technology, and in particular to a method and system for calibrating a splicing error of a spliced ​​objective lens, and a storage medium. Background Art

[0002] With the advancement of digital technology, semiconductor manufacturing, and the advent of the information age, image sensors, as optoelectronic components in the optoelectronics industry, have experienced rapid development. They are now widely used in a variety of fields, each with its own unique customer system requirements. For example, professional imaging applications such as astronomical telescopes, full-frame digital cameras, and medical imaging require large-scale image sensors. Because these large-scale image sensors exceed the image field of photolithography machines, stitching technology is required during the manufacturing process, which naturally requires a method to calibrate exposure stitching errors.

[0003] Currently, an existing method for calibrating exposure stitching errors is to print a stitching pattern on a substrate using a laser direct writing method, measure the deformation of the stitching pattern at the stitching point, i.e., the stitching error, and then input the stitching error into a motion controller, and use the displacement of the load to compensate for the pattern stitching error for calibration. Another method for calibrating exposure stitching errors is to provide opaque areas and corresponding paired stitching seam overlay marks at the stitching positions of each adjacent mask stitching layout of the mask layout. During each exposure process of the same layer of chip actual layout of the chip, at the stitching positions of each adjacent stitching actual layout, the corresponding paired two stitching seam overlay marks can be aligned together after two exposures and can achieve overlay alignment of the stitching. However, the above-mentioned stitching technology does not involve stitching the objective lens to meet the requirement of a larger image field of the lithography machine, and the method for calibrating exposure stitching errors lacks a solution for calibrating the stitching error generated by the stitching objective lens. Summary of the Invention

[0004] The object of the present invention is to provide a method and system for calibrating the stitching error of a stitched objective lens, as well as a storage medium, so as to calibrate the stitching error of the stitched objective lens and improve the estimation accuracy of the stitching error of the stitched objective lens.

[0005] To solve the above technical problems, the first aspect of the present invention provides a method for calibrating a stitching error of a stitching objective lens, wherein a plurality of stitching objective lenses are staggered and distributed in two rows, and the method comprises:

[0006] S1, moving a first mark group on the mask into the field of view of a first row of objective lenses, and exposing the first mark group at a predetermined position on the substrate;

[0007] S2, moving the substrate to move the predetermined position exposed with the first mark group into the field of view of the second row of objective lenses, and exposing the second mark group on the mask to the predetermined position of the substrate;

[0008] S3, obtaining a splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses according to actual positions of the first mark group and the second mark group exposed on the substrate;

[0009] S4, performing compensation calibration on the two adjacent objective lenses that need to be spliced ​​according to the splicing error.

[0010] Optionally, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, and the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group.

[0011] Optionally, the first mark group and the second mark group form a plurality of sets of overlay marks at the predetermined positions, and the step of obtaining the splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses in S3 includes:

[0012] S3.1.1, obtaining n groups of overlay marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, wherein n is an integer greater than or equal to 2 and not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​at the predetermined position;

[0013] S3.1.2, obtaining a horizontal stitching error and a vertical stitching error between a first mark and a second mark in each set of overlay marks;

[0014] S3.1.3, calculating the mean horizontal stitching error and the mean vertical stitching error of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0015] Optionally, the first mark group and the second mark group form a plurality of groups of misalignment marks at the predetermined positions, and the step of obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3 includes:

[0016] S3.2.1, obtaining a horizontal movement distance and a vertical movement distance of the substrate;

[0017] S3.2.2, obtaining m groups of misaligned marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, and the position coordinates of the first mark and the second mark in each group of misaligned marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first group of marks, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​are misaligned with each other to form a corresponding group of misaligned marks;

[0018] S3.2.3, based on the position coordinates of the first mark and the second mark in each group of misalignment marks, and the horizontal and vertical movement distances of the substrate, obtain the stitching errors of each group of misalignment marks in the horizontal and vertical directions respectively;

[0019] S3.2.4, averaging the stitching errors of each group of the misalignment marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0020] Optionally, the two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, and the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions; and the step of obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3 includes:

[0021] S3.3.1, obtaining p groups of overlay marks obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced, where p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced;

[0022] S3.3.2, obtaining the position coordinates of each set of overlay marks in the p sets of overlay marks;

[0023] S3.3.3. Obtaining a plurality of grid parameters of each of the two adjacent objective lenses to be spliced, and obtaining a splicing error in the horizontal and vertical directions for each set of overlay marks based on the plurality of grid parameters of each objective lens and the position coordinates of each set of overlay marks;

[0024] S3.3.4, averaging the stitching errors of each set of overlay marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0025] Optionally, the step of compensating and calibrating the two objective lenses to be spliced ​​according to the splicing error in S4 includes: compensating and calibrating one or both of the two objective lenses to be spliced ​​by a translation compensation method and / or a parameter compensation method.

[0026] Optionally, when a translation compensation method is used to perform compensation calibration on the corresponding objective lens, S4 includes:

[0027] S4.1.1, selecting one objective lens from the two objective lenses to be spliced ​​as a reference splicing objective lens, and setting its compensation amount to zero;

[0028] S4.1.2, obtaining a stitching error between the two objective lenses that need to be stitched, and performing translation compensation on the other objective lens of the two objective lenses that need to be stitched using the reference stitching objective lens as a position reference.

[0029] Optionally, the parameters in the parameter compensation method include: horizontal translation, vertical translation, rotation angle and magnification of the objective lens.

[0030] Optionally, the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions, and when obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3, q groups of overlay marks, the position coordinates of each group of overlay marks, and the splicing errors of each group of overlay marks in the horizontal and vertical directions are also obtained, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group; in S4, a parameter compensation method is used to perform compensation calibration on each of the two adjacent objective lenses to be spliced, and S4 includes:

[0031] S4.2.1, obtaining the horizontal translation, vertical translation, rotation angle, and magnification of each objective lens in the two objective lenses to be spliced ​​based on the position coordinates of the q groups of overlay marks and the stitching errors of each group of overlay marks in the horizontal and vertical directions;

[0032] S4.2.2, performing stitching error compensation on each of the two adjacent objective lenses that need to be stitched according to the acquired horizontal translation amount, the vertical translation amount, the rotation angle, and the magnification.

[0033] A second aspect of the present invention provides a system for calibrating a stitching error of a stitched objective lens, the system comprising:

[0034] an exposure module, configured to expose a first mark group on the mask at a predetermined position on the substrate when the first mark group on the mask moves to the field of view of the first row of objective lenses, move the predetermined position exposed to the first mark group to the field of view of the second row of objective lenses, and expose a second mark group on the mask at the predetermined position on the substrate;

[0035] an acquisition module, configured to acquire a splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses according to actual positions of the first mark group and the second mark group exposed on the substrate;

[0036] The compensation calibration module is used to perform compensation calibration on the two adjacent objective lenses that need to be spliced ​​according to the splicing error.

[0037] Optionally, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlaid marks at the predetermined positions; the acquisition module is specifically configured to:

[0038] Obtaining n groups of overlay marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, wherein n is an integer greater than or equal to 2 and n is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​constitute a corresponding group of overlay marks;

[0039] Obtaining a horizontal splicing error and a vertical splicing error between a first mark and a second mark in each set of overlay marks;

[0040] Calculate the mean horizontal stitching error and the mean vertical stitching error of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0041] Optionally, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of misaligned marks at the predetermined positions, and the acquisition module is further configured to:

[0042] Obtaining a horizontal movement distance and a vertical movement distance of the substrate;

[0043] Obtaining m groups of misaligned marks obtained at the predetermined position by exposure of the two adjacent objective lenses that need to be spliced, as well as position coordinates of a first mark and a second mark in each group of misaligned marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses that need to be spliced ​​are misaligned with each other to form a corresponding group of misaligned marks;

[0044] Obtaining stitching errors of each group of misalignment marks in the horizontal direction and the vertical direction, respectively, according to the position coordinates of the first mark and the second mark in each group of misalignment marks, and the horizontal movement distance and the vertical movement distance of the substrate;

[0045] The stitching errors of each group of the misalignment marks in the horizontal direction and the vertical direction are averaged to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0046] Optionally, the two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions; and the acquisition module is further used to:

[0047] Acquire p groups of overlay marks obtained by exposure at the predetermined position by the two adjacent objective lenses that need to be spliced, wherein p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure at the predetermined position by the two adjacent objective lenses that need to be spliced ​​constitute a corresponding group of overlay marks;

[0048] Obtaining the position coordinates of each set of overlay marks in the p sets of overlay marks;

[0049] Obtaining a plurality of grid parameters of each of the two adjacent objective lenses to be spliced, and obtaining a splicing error of each group of overlay marks in the horizontal direction and the vertical direction respectively according to the plurality of grid parameters of each objective lens and the position coordinates of each group of overlay marks;

[0050] The stitching errors of each group of overlay marks in the horizontal direction and the vertical direction are averaged to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0051] Optionally, the compensation calibration module performs compensation calibration on one or both of the two objective lenses that need to be spliced ​​by using a translation compensation method and / or a parameter compensation method.

[0052] Optionally, when a translation compensation method is used to perform compensation calibration on the corresponding objective lens, the compensation calibration module is specifically used to:

[0053] Select one objective lens from the two objective lenses that need to be spliced ​​as a reference splicing objective lens, and set its compensation amount to zero;

[0054] A splicing error between the two objective lenses that need to be spliced ​​is obtained, and translation compensation is performed on the other objective lens of the two objective lenses that need to be spliced, taking the reference splicing objective lens as a position reference.

[0055] Optionally, the first mark group includes several first marks, the second mark group includes several second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, the first mark group and the second mark group form multiple groups of overlay marks at the predetermined positions, and the acquisition module also acquires q groups of overlay marks, the position coordinates of each group of overlay marks, and the horizontal and vertical stitching errors of each group of overlay marks when acquiring the stitching error between the two adjacent objective lenses to be spliced, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group; the parameters in the parameter compensation method include: the horizontal translation amount, vertical translation amount, rotation angle and magnification of the objective lens; when the parameter compensation method is used to perform compensation calibration on each of the two adjacent objective lenses to be spliced, the compensation calibration module is specifically used to:

[0056] Obtaining the horizontal translation amount, vertical translation amount, rotation angle, and magnification of each objective lens in the two objective lenses to be spliced ​​according to the position coordinates of the q groups of overlay marks and the splicing errors of each group of overlay marks in the horizontal and vertical directions;

[0057] According to the acquired horizontal translation amount, the vertical translation amount, the rotation angle, and the magnification, stitching error compensation is performed on each of the two adjacent objective lenses that need to be stitched.

[0058] The third aspect of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the computer program implements any of the above-mentioned methods for calibrating the stitching error of a stitched objective lens.

[0059] Compared with the prior art, the technical solution provided by the present invention has at least one of the following beneficial effects:

[0060] The present invention provides a method and system for calibrating the stitching error of stitched objective lenses. The method comprises the following steps: moving a first mark group on a mask into the field of view of a first row of objective lenses, exposing the first row of mark groups at predetermined positions on a substrate, then moving the substrate to move the predetermined positions exposed with the first mark group into the field of view of a second row of objective lenses, and exposing the second mark group on the mask at predetermined positions on the substrate. Based on the actual positions of the marks in the first mark group and the second mark group on the substrate, the stitching error between two adjacent objective lenses to be stitched in the two rows of objective lenses is accurately obtained, and the two adjacent objective lenses to be stitched are compensated and calibrated using the stitching error, thereby improving the estimation accuracy of the stitching error of the objective lenses.

[0061] Furthermore, in the method and system for calibrating the splicing error of spliced ​​objective lenses provided by the present invention, the first mark group and the second mark group are combined into multiple groups of overlay marks or multiple groups of misaligned marks at predetermined positions, and the splicing error between two adjacent objective lenses to be spliced ​​is obtained based on the multiple groups of overlay marks or misaligned marks, and two compensation methods, namely, a translation compensation method and a parameter compensation method, are used to compensate and calibrate the two adjacent objective lenses to be spliced ​​based on the obtained splicing error, which can further improve the calibration accuracy of the objective lens splicing error. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A flow chart of a method for calibrating a splicing error of a spliced ​​objective lens provided by the present invention;

[0063] Figure 2 A schematic diagram of the position of an objective lens provided in one embodiment of the present invention;

[0064] Figures 3 to 9 Schematic diagram of the overlay mark and misalignment mark for objective lens exposure provided by the present invention;

[0065] Figure 10 A structural block diagram of a system for calibrating splicing errors of spliced ​​objective lenses provided by the present invention. DETAILED DESCRIPTION

[0066] In high-generation lithography processes, splicing objective lenses are widely used, and the splicing error of objective lenses is an important factor in determining the yield rate of production lines. In the same machine, the position deviation of different objective lenses exposing the same pattern at the same position on the substrate is called splicing error. Before exposure in the lithography machine, it is necessary to correct the splicing error of the splicing objective lenses to within the corresponding indicators. However, as described in the background art, the current method for calibrating the exposure splicing error is to print a splicing pattern on the substrate using a laser direct writing method, measure the deformation of the splicing pattern at the splicing position, i.e., the splicing error, and then input the splicing error into a motion controller, and calibrate the pattern splicing error using the displacement compensation of the load. Another method for calibrating exposure stitching errors is to provide opaque areas and corresponding pairs of stitching seam overlay marks at the splicing locations of adjacent mask stitching layouts on the mask layout. During each exposure process of the actual chip layout on the same layer of the chip, the corresponding pairs of stitching seam overlay marks at the splicing locations of adjacent stitching actual layouts can be aligned together after two exposures, thereby achieving overlay alignment for the stitching. However, the above stitching technology does not involve stitching the objective lens to meet the requirements of a larger image field of the lithography machine, and the method for calibrating exposure stitching errors lacks a solution for calibrating the stitching errors generated by the objective lens.

[0067] Therefore, it is particularly important to design a method for calibrating the splicing error of the exposure. Specifically, a method is used to design several overlay patterns at the splicing point of the objective lenses, each exposed at the same position on the substrate by different objective lenses. The overlay error at each point of the splicing point is then measured using a measurement device and used as the splicing error between adjacent objective lenses to be spliced. To address this issue, the present invention proposes a method, system, and storage medium for calibrating the splicing error of spliced ​​objective lenses. This method calibrates the splicing error of the objective lenses and improves the estimation accuracy of the splicing error.

[0068] refer to Figure 1 , Figure 1 A flowchart of a method for calibrating stitching errors of stitched objective lenses provided by an embodiment of the present invention. Figure 2 As shown, a plurality of objective lenses a1, a2, a3, a4, a5 and a6 are staggered and distributed in two rows. Specifically, the method for calibrating the stitching error of the stitched objective lenses includes the following steps:

[0069] Step S1, moving a first mark group on the mask into the field of view of a first row of objective lenses, and exposing the first mark group at a predetermined position on the substrate;

[0070] Step S2, moving the substrate to move the predetermined position exposed with the first mark group to the field of view of the second row of stitching objective lenses, and exposing the second mark group on the mask to the predetermined position of the substrate;

[0071] Step S3, obtaining a splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses according to actual positions of the first mark group and the second mark group exposed on the substrate;

[0072] Step S4: performing compensation calibration on the two adjacent objective lenses to be spliced ​​according to the splicing error.

[0073] That is, in the method for calibrating the stitching error of stitched objective lenses provided by the present invention, the first mark group on the mask is moved into the field of view of the first row of objective lenses, and the first row of mark group is exposed to a predetermined position on the substrate. Then, the substrate is moved, and the predetermined position exposed to the first mark group is moved into the field of view of the second row of objective lenses, and the second mark group on the mask is exposed to a predetermined position on the substrate. Then, based on the actual positions of the marks in the first mark group and the second mark group on the substrate, the stitching error between two adjacent objective lenses that need to be stitched in the two rows of objective lenses is accurately obtained, and the two adjacent objective lenses that need to be stitched are compensated and calibrated using the stitching error, thereby improving the estimation accuracy of the objective lens stitching error.

[0074] The following is a further detailed description of the method and system for calibrating stitching errors of stitched objective lenses proposed by the present invention, in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in a highly simplified form and are not to exact scale, and are intended solely to facilitate and clearly illustrate the purposes of the embodiments of the present invention.

[0075] In step S1 , a first mark group on the mask is moved to the field of view of a first row of objective lenses, such as the rows of objective lenses a1 , a3 and a5 , and the first mark group is exposed at a predetermined position on the substrate.

[0076] In step S2, the substrate is moved so that the predetermined position exposed with the first mark group is moved to the field of view of the second row of objective lenses, such as the row of objective lenses a2, a4 and a6, and the second mark group on the mask is exposed at the predetermined position of the substrate, that is, the first mark group and the second mark group are exposed at the same position of the substrate.

[0077] The first marking group includes a plurality of first markings, the second marking group includes a plurality of second markings, and the second markings in the second marking group are arranged in a one-to-one correspondence with the first markings in the first marking group.

[0078] As an example, the patterns of the first mark group and the second mark group on the mask are as follows: Figure 3 Reference Figure 3As shown, 1 is the large frame exposed by the first row of objective lenses, 2 is the small frame exposed by the second row of objective lenses, and when 1 and 2 are exposed at the same position on the substrate, they can form an overlay mark. 3 is the exposure splicing area of ​​adjacent objective lenses, and 4 is the non-splicing area. Of course, 1 can also be the small frame exposed by the first row of objective lenses, and 2 is the large frame exposed by the second row of objective lenses. When 1 and 2 are exposed at the same position on the substrate, they can also form an overlay mark. In this embodiment, the exposure pattern of the first and second rows of objective lenses is not limited to which row must expose a fixed mark such as a large frame or a small frame.

[0079] In step S3, a splicing error between two adjacent objective lenses that need to be spliced ​​in two rows of objective lenses is obtained according to actual positions of the first mark group and the second mark group exposed on the substrate.

[0080] Specifically, during actual exposure, there may be a deviation between the actual positions of the first mark in the first mark group and the second mark in the second mark group exposed on the substrate. Figure 4 As shown, the first mark is a large frame, the second mark is a small frame, and the actual exposure positions of the first mark and the second mark coincide with each other; Figure 5 As shown, there is a deviation between the actual exposure positions of the first mark and the second mark. After the first mark and the second mark are exposed on the substrate, the splicing error between two adjacent objective lenses that need to be spliced ​​in two rows of objective lenses can be obtained based on their actual positions.

[0081] like Figure 6 As shown, the first mark group and the second mark group form multiple groups of overlay marks at the predetermined position. Among them, 11 is a group of overlay marks obtained by exposure, 12 is a mark of the non-splicing area adjacent to the splicing area, and 13 is a mark of the non-splicing area. It should be noted that, Figure 6 The exposure field of view stitched in the display scan direction is not limited to a rectangular or trapezoidal field of view.

[0082] When the first mark group and the second mark group form a plurality of sets of overlay marks at the predetermined positions, the step of obtaining the splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses in S3 includes:

[0083] S3.1.1, obtaining n groups of overlay marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, wherein n is an integer greater than or equal to 2 and not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​at the predetermined position;

[0084] S3.1.2, obtaining a horizontal stitching error and a vertical stitching error between a first mark and a second mark in each set of overlay marks;

[0085] S3.1.3, calculating the mean horizontal stitching error and the mean vertical stitching error of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0086] Specifically, in Figure 6 Obtain n sets of overlay marks from the several sets of overlay marks obtained by exposure 11. Figure 7 As shown, taking the nth group of overlay marks as an example, the horizontal splicing error Δx and the vertical splicing error Δy between the first and second marks in the group of overlay marks can be obtained. When the actual positions of the first and second marks coincide, it is clear that w1 = w2 and w3 = w4. When the actual positions of the first and second marks do not coincide, the horizontal splicing error and the vertical splicing error between the first and second marks in the nth group of overlay marks can be calculated according to the following formula:

[0087]

[0088] in, is the horizontal splicing error of the nth group of overlay marks, is the vertical splicing error of the nth group of overlay marks. Where i and j are the numbers of the objective lenses, for example, objective lens a2 and objective lens a3. When it is positive, it means the second mark deviates to the right; when When it is negative, it means the second mark deviates to the left; when When it is positive, it means the second mark deviates upward; when When negative, it indicates that the second marker deviates downward.

[0089] After calculating the horizontal and vertical splicing errors of the first and second marks in the n sets of overlay marks, the error between objective lens i and objective lens j can be obtained. That is, the mean horizontal stitching error and the mean vertical stitching error of n sets of overlay marks are used to obtain the stitching error between objective lens i and objective lens j, which is

[0090] Optional, such as Figure 8 As shown, the first mark group and the second mark group can form multiple groups of misaligned marks at the predetermined position. Figure 8 In the example, 21 is the first mark exposed by the first row of objective lenses, and 22 is the second mark exposed by the second row of objective lenses. The first mark and the second mark in the first mark group and the second mark group can be any mark used to measure position, such as a cross mark. The step of obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3 includes:

[0091] S3.2.1, obtaining a horizontal movement distance and a vertical movement distance of the substrate;

[0092] S3.2.2, obtaining m groups of misaligned marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, and the position coordinates of the first mark and the second mark in each group of misaligned marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first group of marks, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​are misaligned with each other to form a corresponding group of misaligned marks;

[0093] S3.2.3, based on the position coordinates of the first mark and the second mark in each group of misalignment marks, and the horizontal and vertical movement distances of the substrate, obtain the stitching errors of each group of misalignment marks in the horizontal and vertical directions respectively;

[0094] S3.2.4, averaging the stitching errors of each group of the misalignment marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0095] Specifically, a fixed offset can be made between the cross marks exposed at predetermined positions by the first and second rows of objective lenses to obtain multiple sets of misaligned marks, and then the positional deviation of the first mark and the second mark is obtained, and the stitching error can be obtained by subtracting the fixed offset.

[0096] As an example, the horizontal movement distance dx and the vertical movement distance dy of the substrate are obtained, and then m groups of misalignment marks obtained by exposure between two adjacent objective lenses to be spliced, such as objective lens i and objective lens j, at the predetermined position are obtained. Taking the mth group of misalignment marks as an example, the position coordinates of the first mark and the position coordinates of the second mark in the mth group of misalignment marks are obtained {(p1x ij ,p1y ij ),(p2x ij ,p2y ij )}, and then the splicing error of the mth group of misaligned marks is obtained according to the following formula:

[0097]

[0098] in, is the splicing error of the mth group of misaligned marks in the horizontal direction, is the splicing error of the mth group of misaligned marks in the vertical direction.

[0099] After calculating the stitching error of the mth group of misaligned marks, the stitching errors of each group of misaligned marks in the horizontal and vertical directions can be calculated accordingly, and then the average stitching errors of the m groups of misaligned marks in the horizontal and vertical directions are calculated respectively to obtain the stitching error between the objective lens i and the objective lens j.

[0100] like Figure 9 As shown, the two objective lenses to be spliced ​​may also be two adjacent objective lenses in the same row in the non-scanning direction. Reference numeral 31 denotes the left objective lens, reference numeral 32 denotes the right objective lens, reference numeral 33 denotes the area on the substrate where the left and right objective lenses need to be spliced, and reference numeral 34 denotes the substrate. When the two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, and the first mark group and the second mark group form a plurality of sets of overlay marks at the predetermined positions, the step of obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3 includes:

[0101] S3.3.1, obtaining p groups of overlay marks obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced, where p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced;

[0102] S3.3.2, obtaining the position coordinates of each set of overlay marks in the p sets of overlay marks;

[0103] S3.3.3. Obtaining a plurality of grid parameters of each of the two adjacent objective lenses to be spliced, and obtaining a splicing error in the horizontal and vertical directions for each set of overlay marks based on the plurality of grid parameters of each objective lens and the position coordinates of each set of overlay marks;

[0104] S3.3.4, averaging the stitching errors of each set of overlay marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

[0105] Specifically, first, expose between adjacent objective lenses i and j in the non-scanning direction row to obtain p groups of overlay marks. Taking the pth group of overlay marks as an example, obtain the position coordinates of the pth group of overlay marks, such as {x, y}, and then obtain several grid parameters of objective lens i, such as K1_i, K2_i, K3_i, ..., K20_i, ..., and then calculate the grid description parameters Len_x_i and Len_y_i of objective lens i based on the position coordinates {x, y} of the pth group of overlay marks. Specifically, they are calculated according to the following formula:

[0106] Len_x_i=K1_i+K3_i·x+K5_i·y+K7_i·x 2 +K9_i·x·y+K11_i·y 2 +K13_i·x 3 +K15_i·x 2 ·y+K17_i·x·y 2 +K19_i·y 3 +...

[0107] Len_y_i=K2_i+K4_i·y+K6_i·x+K8_i·y 2 +K10_i·y·x+K12_i·x 2 +K14_i·y 3 +K16_i·y 2 ·x+K18_i·y·x 2 +K20_i·x 3 +... (2)

[0109] Similarly, several grid parameters of objective lens j are obtained, such as K1_j, K2_j, K3_j, ..., K20_j, ..., and then the grid description parameters Len_x_j and Len_y_j of objective lens j are calculated according to the position coordinates {x, y} of the pth group of overlay marks.

[0110] Furthermore, based on the grid description parameters Len_x_i(p) and Len_y_i(p) of objective lens i under the p-th group of overlay marks, and the grid description parameters Len_x_j(p) and Len_y_j(p) of objective lens j, the stitching errors of the p-th group of overlay marks in the horizontal and vertical directions are calculated by the following formulas:

[0111]

[0112] After calculating the stitching errors of all p groups of overlay marks in the horizontal and vertical directions, the stitching errors of each group of overlay marks in the horizontal and vertical directions are averaged to obtain the stitching error between the objective lens i and the objective lens j.

[0113] Optionally, the step of compensating and calibrating the two objective lenses to be spliced ​​according to the splicing error in S4 includes: compensating and calibrating one or both of the two objective lenses to be spliced ​​by a translation compensation method and / or a parameter compensation method.

[0114] The parameters in the parameter compensation method include: the horizontal translation amount, vertical translation amount, rotation angle and magnification of the objective lens.

[0115] When the translation compensation method is used to perform compensation calibration on the corresponding objective lens, S4 includes:

[0116] S4.1.1, selecting one objective lens from the two objective lenses to be spliced ​​as a reference splicing objective lens, and setting its compensation amount to zero;

[0117] S4.1.2, obtaining a stitching error between the two objective lenses that need to be stitched, and performing translation compensation on the other objective lens of the two objective lenses that need to be stitched using the reference stitching objective lens as a position reference.

[0118] Specifically, take a certain objective lens as the reference, fix its position unchanged, and adjust the other objective lenses according to the measured splicing error as follows: Move closer to the objective lens. If the middle objective lens is selected as the reference, let the middle objective lens number be c, and its compensation amount is EC c ={0,0}, then the translation compensation of other objective lenses is:

[0119]

[0120] As an example, consider objective lens a3, whose adjacent objective lenses are objective lenses a2 and a4. Objective lens a3 is selected as the reference for stitching the objective lenses. The stitching error between objective lenses a2 and a3 is calculated. Then, using objective lens a3 as the reference, objective lens a2 is translated by the stitching error. Similarly, the stitching error between objective lenses a4 and a3 is calculated. Then, using objective lens a3 as the reference, objective lens a4 is translated by the stitching error between objective lenses a4 and a3, thereby achieving compensation calibration of the objective lenses.

[0121] Optionally, the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions, and when obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3, q groups of overlay marks, the position coordinates of each group of overlay marks, and the splicing errors of each group of overlay marks in the horizontal and vertical directions are also obtained, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group; in S4, a parameter compensation method is used to perform compensation calibration on each of the two objective lenses to be spliced, and S4 includes:

[0122] S4.2.1, obtaining the horizontal translation, vertical translation, rotation angle, and magnification of each objective lens in the two objective lenses to be spliced ​​based on the position coordinates of the q groups of overlay marks and the stitching errors of each group of overlay marks in the horizontal and vertical directions;

[0123] S4.2.2, performing stitching error compensation on each of the two adjacent objective lenses that need to be stitched according to the acquired horizontal translation amount, the vertical translation amount, the rotation angle, and the magnification.

[0124] Specifically, taking adjacent objective lenses i and j as an example, q groups of overlay marks obtained by exposure between adjacent objective lenses i and j can be obtained, where q needs to be at least greater than or equal to 4 and less than the number of first marks in the first mark group, so as to calculate the horizontal translation amount, vertical translation amount, rotation angle and magnification of each objective lens. When obtaining q groups of overlay marks obtained by exposure between adjacent objective lenses i and j, the position coordinates of each group of overlay marks are correspondingly obtained, such as {x ij q ,y ij q}, and the splicing errors of each set of overlay marks in the horizontal and vertical directions are as follows and

[0125] Furthermore, the four parameters {Tx i ,Ty i ,θ i ,M i} and {Tx j ,Ty j ,θ j ,M j}. Among them, Tx i 、Ty i ,θ i and M i are the horizontal translation, vertical translation, rotation angle and magnification of objective lens i respectively; Tx j 、Ty j ,θ j and M j are the horizontal translation, vertical translation, rotation angle and magnification of objective lens j respectively. Then, the splicing error description between objective lens i and objective lens j is established based on the above parameters:

[0126]

[0127] Among them, δx ij is the horizontal stitching error between objective lens i and objective lens j, δy ij is the stitching error between objective lens i and objective lens j in the vertical direction, x is the abscissa of the overlay mark, and y is the ordinate of the overlay mark.

[0128] Furthermore, based on the position coordinates of each group of overlay marks, taking the qth group of overlay marks as an example, the following matrix equation is established:

[0129]

[0130] in, and are the position coordinates of the qth group of overlay marks, and is the stitching error of the qth group of overlay marks in the horizontal and vertical directions. When the overlay marks in formula (5) are the qth group of overlay marks, formula (5) can be substituted into formula (6) to establish the first matrix formula. Since q is an integer greater than or equal to 4, at least four matrix formulas can be obtained to obtain the horizontal translation, vertical translation, rotation angle, and magnification of each objective lens. Then, each objective lens is compensated and calibrated according to the four parameters obtained for each objective lens.

[0131] The second aspect of the present invention also provides a system for calibrating the stitching error of a stitched objective lens, such as Figure 10 As shown, the system 10 for calibrating stitching errors of stitched objective lenses includes: an exposure module 11 , an acquisition module 12 and a compensation calibration module 13 .

[0132] The exposure module 11 is configured to expose the first mark group on the mask at a predetermined position on the substrate when the first mark group moves to the field of view of the first row of objective lenses, move the predetermined position exposed with the first mark group to the field of view of the second row of objective lenses, and expose the second mark group on the mask at the predetermined position on the substrate. The acquisition module 12 is configured to obtain the splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses based on the actual positions at which the first mark group and the second mark group are exposed on the substrate. The compensation calibration module 13 is configured to perform compensation calibration on the two adjacent objective lenses to be spliced ​​based on the splicing error.

[0133] Optionally, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlaid marks at the predetermined positions; the acquisition module 12 is specifically configured to:

[0134] Obtain n groups of overlay marks obtained by exposure of the two adjacent objective lenses to be spliced ​​at the predetermined position, wherein n is an integer greater than or equal to 2 and n is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​constitute a corresponding group of overlay marks; obtain horizontal stitching errors and vertical stitching errors between the first mark and the second mark in each group of overlay marks; calculate the average horizontal stitching errors and the average vertical stitching errors of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses to be spliced.

[0135] Optionally, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of misaligned marks at the predetermined positions, and the acquisition module 12 is further configured to:

[0136] Obtain a horizontal movement distance and a vertical movement distance of the substrate; obtain m groups of misalignment marks obtained by exposure of the two adjacent objective lenses to be spliced ​​at the predetermined position, and the position coordinates of the first mark and the second mark in each group of misalignment marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​are misaligned with each other to form a corresponding group of misalignment marks; obtain a splicing error of each group of misalignment marks in the horizontal direction and the vertical direction respectively according to the position coordinates of the first mark and the position coordinates of the second mark in each group of misalignment marks, and the horizontal movement distance and the vertical movement distance of the substrate; and average the splicing errors of each group of misalignment marks in the horizontal direction and the vertical direction respectively to obtain the splicing error between the two adjacent objective lenses to be spliced.

[0137] Optionally, the two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions; the acquisition module 12 is further used to:

[0138] Obtain p groups of overlay marks obtained by exposing the two adjacent objective lenses to be spliced ​​at the predetermined position, wherein p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark are obtained by exposing the two adjacent objective lenses to be spliced, forming a corresponding group of overlay marks; obtain the position coordinates of each group of overlay marks in the p groups of overlay marks; obtain a number of grid parameters of each of the two adjacent objective lenses to be spliced, and obtain the splicing errors of each group of overlay marks in the horizontal and vertical directions according to the several grid parameters of each objective lens and the position coordinates of each group of overlay marks; and average the splicing errors of each group of overlay marks in the horizontal and vertical directions to obtain the splicing error between the two adjacent objective lenses to be spliced.

[0139] Optionally, the compensation calibration module 13 performs compensation calibration on one or both of the two objective lenses that need to be spliced ​​by using a translation compensation method and / or a parameter compensation method.

[0140] Optionally, when a translation compensation method is used to perform compensation calibration on the corresponding objective lens, the compensation calibration module 13 is specifically used to:

[0141] One objective lens is selected from the two objective lenses that need to be spliced ​​as a reference splicing objective lens, and its compensation amount is set to zero; the splicing error between the two objective lenses that need to be spliced ​​is obtained, and the reference splicing objective lens is used as a position reference to perform translation compensation on the other objective lens of the two objective lenses that need to be spliced.

[0142] Optionally, the first mark group includes several first marks, the second mark group includes several second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, the first mark group and the second mark group form multiple groups of overlay marks at the predetermined positions, and the acquisition module 12 also acquires q groups of overlay marks, the position coordinates of each group of overlay marks, and the horizontal and vertical stitching errors of each group of overlay marks when acquiring the stitching error between the two adjacent objective lenses to be spliced, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group; the parameters in the parameter compensation method include: the horizontal translation amount, vertical translation amount, rotation angle and magnification of the objective lens; when the parameter compensation method is used to perform compensation calibration on each of the two objective lenses to be spliced, the compensation calibration module 13 is specifically used to:

[0143] According to the position coordinates of the q groups of overlay marks and the stitching errors of each group of overlay marks in the horizontal and vertical directions, the horizontal translation, vertical translation, rotation angle and magnification of each objective lens that need to be stitched are obtained; and according to the obtained horizontal translation, vertical translation, rotation angle and magnification, stitching error compensation is performed on each objective lens that need to be stitched.

[0144] It should be noted that the specific implementation of the system for calibrating the stitching error of a stitched objective lens according to the embodiment of the present invention can be found in the specific implementation of the method for calibrating the stitching error of a stitched objective lens described above, which will not be repeated here.

[0145] The present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the computer program implements the above-mentioned method for calibrating the stitching error of a stitched objective lens.

[0146] In summary, the present invention provides a method and system for calibrating the stitching error of stitched objective lenses. The method and system move the first mark group on the mask into the field of view of the first row of objective lenses, expose the first row of mark group at a predetermined position on the substrate, and then move the substrate to move the predetermined position exposed to the first mark group into the field of view of the second row of objective lenses, and expose the second mark group on the mask at a predetermined position on the substrate. Then, based on the actual positions of the marks in the first mark group and the second mark group on the substrate, the stitching error between two adjacent objective lenses that need to be stitched in the two rows of objective lenses is accurately obtained, and the two adjacent objective lenses that need to be stitched are compensated and calibrated using the stitching error, thereby improving the estimation accuracy of the objective lens stitching error.

[0147] Furthermore, in the method and system for calibrating the splicing error of spliced ​​objective lenses provided by the present invention, the first mark group and the second mark group are combined into multiple groups of overlay marks or multiple groups of misaligned marks at predetermined positions, and the splicing error between two adjacent objective lenses to be spliced ​​is obtained based on the multiple groups of overlay marks or misaligned marks, and two compensation methods, namely, a translation compensation method and a parameter compensation method, are used to compensate and calibrate the two adjacent objective lenses to be spliced ​​based on the obtained splicing error, which can further improve the calibration accuracy of the objective lens splicing error.

[0148] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of protection of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the present invention.

[0149] It should be noted that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or to modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

[0150] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A method for calibrating stitching errors of stitched objective lenses, wherein: A plurality of objective lenses are staggered and distributed in two rows, wherein the method comprises: S1, moving a first mark group on the mask into the field of view of a first row of objective lenses, and exposing the first mark group at a predetermined position on the substrate; S2, moving the substrate to move the predetermined position exposed with the first mark group into the field of view of the second row of objective lenses, and exposing the second mark group on the mask to the predetermined position of the substrate; S3, obtaining a splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses according to actual positions of the first mark group and the second mark group exposed on the substrate; S4, performing compensation calibration on the two adjacent objective lenses that need to be spliced ​​according to the splicing error.

2. The method for calibrating the stitching error of a stitched objective lens according to claim 1, wherein: The first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, and the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group.

3. The method for calibrating the stitching error of a stitched objective lens according to claim 2, wherein: The first mark group and the second mark group form a plurality of sets of overlay marks at the predetermined positions, and the step of obtaining the splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses in S3 includes: S3.1.1, obtaining n groups of overlay marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, wherein n is an integer greater than or equal to 2 and not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​at the predetermined position; S3.1.2, obtaining a horizontal stitching error and a vertical stitching error between a first mark and a second mark in each set of overlay marks; S3.1.3, calculating the mean horizontal stitching error and the mean vertical stitching error of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

4. The method for calibrating the stitching error of a stitched objective lens according to claim 2, wherein: The first mark group and the second mark group form a plurality of groups of misalignment marks at the predetermined positions, and the step of obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3 includes: S3.2.1, obtaining a horizontal movement distance and a vertical movement distance of the substrate; S3.2.2, obtaining m groups of misaligned marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, and the position coordinates of the first mark and the second mark in each group of misaligned marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first group of marks, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​are misaligned with each other to form a corresponding group of misaligned marks; S3.2.3, based on the position coordinates of the first mark and the second mark in each group of misalignment marks, and the horizontal and vertical movement distances of the substrate, obtain the stitching errors of each group of misalignment marks in the horizontal and vertical directions respectively; S3.2.4, averaging the stitching errors of each group of the misalignment marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

5. The method for calibrating the stitching error of a stitched objective lens according to claim 2, wherein: The two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, and the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions; The step of obtaining the stitching error between the two adjacent objective lenses to be stitched in S3 includes: S3.3.1, obtaining p groups of overlay marks obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced, where p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and a corresponding group of overlay marks is formed by a corresponding first mark and a corresponding second mark obtained by exposure at the predetermined position by the two adjacent objective lenses to be spliced; S3.3.2, obtaining the position coordinates of each set of overlay marks in the p sets of overlay marks; S3.3.

3. Obtaining a plurality of grid parameters of each of the two adjacent objective lenses to be spliced, and obtaining a splicing error in the horizontal and vertical directions for each set of overlay marks based on the plurality of grid parameters of each objective lens and the position coordinates of each set of overlay marks; S3.3.4, averaging the stitching errors of each set of overlay marks in the horizontal direction and the vertical direction, respectively, to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

6. The method for calibrating stitching errors of stitched objective lenses according to claim 1, wherein: The step of compensating and calibrating the two objective lenses to be spliced ​​according to the splicing error in S4 includes: compensating and calibrating one or both of the two objective lenses to be spliced ​​by a translation compensation method and / or a parameter compensation method.

7. The method for calibrating stitching errors of stitched objective lenses according to claim 6, wherein: When the translation compensation method is used to perform compensation calibration on the corresponding objective lens, S4 includes: S4.1.1, selecting one objective lens from the two objective lenses to be spliced ​​as a reference splicing objective lens, and setting its compensation amount to zero; S4.1.2, obtaining a stitching error between the two objective lenses that need to be stitched, and performing translation compensation on the other objective lens of the two objective lenses that need to be stitched using the reference stitching objective lens as a position reference.

8. The method for calibrating stitching errors of stitched objective lenses according to claim 6, wherein: The parameters in the parameter compensation method include: the horizontal translation amount, vertical translation amount, rotation angle and magnification of the objective lens.

9. The method for calibrating stitching errors of stitched objective lenses according to claim 8, wherein: The first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions. When obtaining the splicing error between the two adjacent objective lenses to be spliced ​​in S3, q groups of overlay marks, the position coordinates of each group of overlay marks, and the splicing errors of each group of overlay marks in the horizontal and vertical directions are also obtained, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group. In S4, a parameter compensation method is used to perform compensation calibration on each of the two adjacent objective lenses to be spliced, and S4 includes: S4.2.1, obtaining the horizontal translation, vertical translation, rotation angle, and magnification of each objective lens in the two objective lenses to be spliced ​​based on the position coordinates of the q groups of overlay marks and the stitching errors of each group of overlay marks in the horizontal and vertical directions; S4.2.2, performing stitching error compensation on each of the two adjacent objective lenses that need to be stitched according to the acquired horizontal translation amount, the vertical translation amount, the rotation angle, and the magnification.

10. A system for calibrating stitching errors of stitched objective lenses, characterized in that: The system comprises: an exposure module, configured to expose a first mark group on the mask at a predetermined position on the substrate when the first mark group on the mask moves to the field of view of the first row of objective lenses, move the predetermined position exposed to the first mark group to the field of view of the second row of objective lenses, and expose a second mark group on the mask at the predetermined position on the substrate; an acquisition module, configured to acquire a splicing error between two adjacent objective lenses to be spliced ​​in two rows of objective lenses according to actual positions of the first mark group and the second mark group exposed on the substrate; The compensation calibration module is used to perform compensation calibration on the two adjacent objective lenses that need to be spliced ​​according to the splicing error.

11. The system for calibrating stitching errors of a stitched objective lens according to claim 10, wherein: The first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlaid marks at the predetermined positions; the acquisition module is specifically configured to: Obtaining n groups of overlay marks obtained at the predetermined position by exposure of the two adjacent objective lenses to be spliced, wherein n is an integer greater than or equal to 2 and n is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses to be spliced ​​constitute a corresponding group of overlay marks; Obtaining a horizontal splicing error and a vertical splicing error between a first mark and a second mark in each set of overlay marks; Calculate the mean horizontal stitching error and the mean vertical stitching error of the n groups of overlay marks to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

12. The system for calibrating stitching errors of a stitched objective lens according to claim 10, wherein: The first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of misaligned marks at the predetermined position, and the acquisition module is further used to: Obtaining a horizontal movement distance and a vertical movement distance of the substrate; Obtaining m groups of misaligned marks obtained at the predetermined position by exposure of the two adjacent objective lenses that need to be spliced, as well as position coordinates of a first mark and a second mark in each group of misaligned marks, wherein m is an integer greater than or equal to 2 and m is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure of the two adjacent objective lenses that need to be spliced ​​are misaligned with each other to form a corresponding group of misaligned marks; Obtaining stitching errors of each group of misalignment marks in the horizontal direction and the vertical direction, respectively, according to the position coordinates of the first mark and the second mark in each group of misalignment marks, and the horizontal movement distance and the vertical movement distance of the substrate; The stitching errors of each group of the misalignment marks in the horizontal direction and the vertical direction are averaged to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

13. The system for calibrating stitching errors of a stitched objective lens according to claim 10, wherein: The two objective lenses to be spliced ​​are two adjacent objective lenses in the same row in the non-scanning direction, the first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, and the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions; the acquisition module is further used for: Acquire p groups of overlay marks obtained by exposure at the predetermined position by the two adjacent objective lenses that need to be spliced, wherein p is an integer greater than or equal to 2 and p is not greater than the number of first marks in the first mark group, and at the predetermined position, a corresponding first mark and a corresponding second mark obtained by exposure at the predetermined position by the two adjacent objective lenses that need to be spliced ​​constitute a corresponding group of overlay marks; Obtaining the position coordinates of each set of overlay marks in the p sets of overlay marks; Obtaining a plurality of grid parameters of each of the two adjacent objective lenses to be spliced, and obtaining a splicing error of each group of overlay marks in the horizontal direction and the vertical direction respectively according to the plurality of grid parameters of each objective lens and the position coordinates of each group of overlay marks; The stitching errors of each group of overlay marks in the horizontal direction and the vertical direction are averaged to obtain the stitching error between the two adjacent objective lenses that need to be stitched.

14. The system for calibrating stitching errors of a stitched objective lens according to claim 10, wherein: The compensation calibration module performs compensation calibration on one or both of the two objective lenses that need to be spliced ​​through a translation compensation method and / or a parameter compensation method.

15. The system for calibrating stitching errors of a stitched objective lens according to claim 14, wherein: When the translation compensation method is used to perform compensation calibration on the corresponding objective lens, the compensation calibration module is specifically used to: Select one objective lens from the two objective lenses that need to be spliced ​​as a reference splicing objective lens, and set its compensation amount to zero; A splicing error between the two objective lenses that need to be spliced ​​is obtained, and translation compensation is performed on the other objective lens of the two objective lenses that need to be spliced, taking the reference splicing objective lens as a position reference.

16. The system for calibrating stitching errors of a stitched objective lens according to claim 14, wherein: The first mark group includes a plurality of first marks, the second mark group includes a plurality of second marks, the second marks in the second mark group are arranged in a one-to-one correspondence with the first marks in the first mark group, the first mark group and the second mark group form a plurality of groups of overlay marks at the predetermined positions, and the acquisition module also acquires q groups of overlay marks, the position coordinates of each group of overlay marks, and the horizontal and vertical splicing errors of each group of overlay marks when acquiring the splicing error between the two adjacent objective lenses to be spliced, wherein q is an integer greater than or equal to 4 and q is less than the number of first marks in the first mark group; the parameters in the parameter compensation method include: the horizontal translation amount, vertical translation amount, rotation angle and magnification of the objective lens; when the parameter compensation method is used to perform compensation calibration on each of the two adjacent objective lenses to be spliced, the compensation calibration module is specifically used to: Obtaining the horizontal translation amount, vertical translation amount, rotation angle, and magnification of each objective lens in the two objective lenses to be spliced ​​according to the position coordinates of the q groups of overlay marks and the splicing errors of each group of overlay marks in the horizontal and vertical directions; According to the acquired horizontal translation amount, the vertical translation amount, the rotation angle, and the magnification, stitching error compensation is performed on each of the two adjacent objective lenses that need to be stitched.

17. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the computer program implements the method for calibrating a stitching error of a stitched objective lens according to any one of claims 1 to 9.

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