Overlay precision error detection method, storage medium and terminal

Abstract

The invention discloses an overlay precision error detection method, a storage medium and a terminal. The method comprises the following steps: acquiring an initial design layout; obtaining an initial measurement layout through the initial design layout; first image processing is conducted on the initial design layout, a first transition layout is obtained, and the first transition layout comprises a plurality of first transition graphs corresponding to the design graphs; a first measurement area is arranged in the first transition layout, a first transition graph in the first measurement area is obtained to serve as a first measurement graph, and the first measurement graph has position information in the first transition layout; second image processing is conducted on the initial measurement layout, a second transition layout is obtained, and the second transition layout comprises a plurality of second transition graphs corresponding to the actual graphs; according to the position information of the measurement graph, extracting an effective graph corresponding to the first measurement graph from the plurality of second transition graphs; acquiring a second measurement area in the initial measurement layout according to the position of the effective graph; according to the overlay precision error detection method, the first measurement pattern on the initial design layout is obtained, the first measurement pattern is combined with the second transition pattern, and then the effective pattern corresponding to the first measurement pattern in the second transition layout and the position of the effective pattern are obtained. The position of the effective pattern corresponds to the position of the measurement frame, so that the second measurement area is obtained, namely, the position of the measurement frame in the initial measurement layout is determined, and the accuracy and efficiency of subsequent overlay precision error detection are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an overlay accuracy error detection method, a storage medium and a terminal. Background Art

[0002] With the development of semiconductor technology, the reduction of critical dimensions has reached the limit of photolithography. For example, small HTH can no longer be achieved, so it is necessary to add a mask to introduce a cut layer to complete it.

[0003] However, during the AEI (Post-Etch Inspection) stage (AEI) measurement, the cut layer is subject to interference from the preceding layer. Consequently, the machine cannot accurately grasp the measurement frame position, resulting in inaccurate measurement results and requiring manual processing. Furthermore, as critical dimensions decrease, a large number of patterns need to be measured for confirmation, leading to a large amount of manual processing and a very time-consuming process. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide an overlay accuracy error detection method, a storage medium and a terminal to improve the accuracy and efficiency of image measurement.

[0005] To solve the above technical problems, an embodiment of the present invention provides an overlay accuracy error detection method, comprising: obtaining an initial design layout, wherein the initial design layout includes a plurality of design graphics; obtaining an initial measurement layout through the initial design layout, wherein the initial measurement layout includes a plurality of actual graphics corresponding to the design graphics; performing a first image processing on the initial design layout to obtain a first transition layout, wherein the first transition layout includes a plurality of first transition graphics corresponding to the plurality of the design graphics; setting a first measurement area in the first transition layout, and obtaining a first transition graphic in the first measurement area as a first measurement graphic, wherein the first measurement graphic has position information in the first transition layout; performing a second image processing on the initial measurement layout to obtain a second transition layout, wherein the second transition layout includes a plurality of second transition graphics corresponding to the plurality of the actual graphics; extracting a valid graphic corresponding to the first measurement graphic from the plurality of second transition graphics according to the position information of the measurement graphics; and obtaining a second measurement area in the initial measurement layout according to the position of the valid graphic.

[0006] In one possible design, in another implementation of another aspect of the embodiment of the present application, the first image processing method includes: first performing channel extraction processing on the design graphic, and the channel extraction processing is used to grayscale the design graphic; and after the channel extraction processing, performing binarization processing on the design graphic, and the binarization processing is used to black and white the design graphic to obtain a first transitional layout with clear contours.

[0007] In one possible design, in another implementation of another aspect of the embodiment of the present application, the second image processing method includes: performing morphological opening operation on the actual graphic, and the morphological opening operation is used to remove interfering graphics in the actual graphic to obtain a second transition map.

[0008] In one possible design, in another implementation of another aspect of an embodiment of the present application, a method for performing morphological opening processing on an initial measurement layout includes: first performing an erosion process on the actual graphic, and then performing an expansion process after the erosion process to obtain a first initial measurement layout; performing contour extraction processing on the first initial measurement layout, wherein the contour extraction processing is used to obtain the contour of the actual graphic; after the contour extraction processing, performing a minimum area screening process on the contour of the actual graphic, wherein the minimum area screening process is used to remove invalid areas in the contour of the actual graphic, and obtain a second transition layout.

[0009] In one possible design, in another implementation of another aspect of the embodiment of the present application, the second image processing method also includes: before performing morphological opening operation on the actual graphic, performing median filtering denoising on the actual graphic, the median filtering denoising is used to set the pixel points in the actual graphic to the median of the grayscale values ​​of all pixels to denoise the actual graphic; and performing binarization after the median filtering denoising, the binarization is used to perform black and white processing on the actual graphic to obtain an initial measurement layout with clear contours.

[0010] In one possible design, in another implementation of another aspect of the embodiment of the present application, a method for obtaining a second measurement area in the initial measurement layout based on the position of the effective graphic includes: after obtaining the position of the effective graphic, locating the center position of the initial measurement layout based on the position of the effective graphic; based on the center position and the second measurement area, correcting the position of the measurement frame in the initial measurement layout, the position of the corrected measurement frame is axially symmetrical about the center position, and the position of the second measurement area corresponds to the position of the corrected measurement frame.

[0011] In one possible design, in another implementation of another aspect of an embodiment of the present application, a method for extracting a valid graphic corresponding to the first measurement graphic from several second transition graphics includes: extracting an overlapping portion of the first measurement graphic and the second transition graphic, the overlapping portion being a valid graphic in the second transition graphic.

[0012] In one possible design, in another implementation of another aspect of the embodiment of the present application, the overlay accuracy error detection method further includes: obtaining an actual pattern within the second measurement area as a second measurement pattern; and performing an overlay accuracy test on the second measurement pattern.

[0013] Correspondingly, the technical solution of the present invention further provides a storage medium on which computer instructions are stored, and when the computer instructions are executed, the steps of the above-mentioned overlay accuracy error detection method are executed.

[0014] Correspondingly, the technical solution of the present invention also provides a terminal, including a memory and a processor, wherein the memory stores computer instructions that can be run on the processor, and the processor executes the steps of the above-mentioned overlay accuracy error detection method when running the computer instructions.

[0015] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0016] In the overlay accuracy error detection method provided by the technical solution of the present invention, the initial design layout is the design graphic, and the initial measurement layout is the actual graphic. Due to the presence of a large number of interference graphics on the initial measurement layout, the positioning of the measurement frame is offset, while the graphics on the initial design layout are relatively regular. By obtaining the first measurement graphic on the initial design layout and combining the first measurement graphic with the second transition graphic, the valid graphic corresponding to the first measurement graphic and the position of the valid graphic in the second transition layout are obtained. Since the valid graphic is the detection object of the overlay accuracy error detection, the position of the valid graphic corresponds to the position of the measurement frame, and thus the second measurement area is obtained, that is, the position of the measurement frame in the initial measurement layout is determined, thereby improving the accuracy and efficiency of subsequent overlay accuracy error detection; in addition, in the technical solution of the present invention, before obtaining the first measurement graphic and the valid graphic, the initial design layout and the initial measurement layout are image processed, so that the first measurement graphic and the valid graphic are clearer, further improving the accuracy and efficiency of overlay accuracy error detection.

[0017] Furthermore, the technical solution of the present invention uses the actual pattern in the second measurement area as the second measurement pattern and performs an overlay accuracy test on the second measurement pattern. Since the second measurement pattern corresponds to the first measurement pattern, and the first measurement pattern is obtained from the design pattern, the accuracy of the position positioning of the second measurement area is achieved, thereby improving the accuracy and efficiency of subsequent overlay accuracy error detection.

[0018] Furthermore, the technical solution of the present invention performs channel extraction processing on the initial design layout first, and then performs binarization processing on the initial design layout, so that the initial design layout is grayscaled and the fine line interference in the initial design layout is removed to obtain a first transition figure with a clear outline, thereby improving the accuracy of subsequent positioning of the first measurement area and the positioning of the first measurement figure.

[0019] Furthermore, the technical solution of the present invention performs median filtering denoising and binarization processing on the initial measurement layout to obtain an initial measurement layout with clear contours, and uses morphological opening operation processing to first erode the initial measurement layout and then perform dilation processing to disconnect or remove fine lines in the interference pattern, thereby further clarifying the initial measurement layout and improving the accuracy of the second measurement area positioning and overlay accuracy test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 1 ;

[0021] Figure 2 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 2 ;

[0022] Figure 3 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 3 ;

[0023] Figure 4 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 4 ;

[0024] Figure 5 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 5 ;

[0025] Figure 6 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 1 ;

[0026] Figure 7 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 2 ;

[0027] Figure 8 This is a schematic diagram of the structure of the initial measurement layout in one embodiment of the present invention. Figure 1 ;

[0028] Figure 9 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 1 ;

[0029] Figure 10 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 2 ;

[0030] Figure 11 This is a schematic diagram of the structure of the initial measurement layout in one embodiment of the present invention. Figure 2 . DETAILED DESCRIPTION

[0031] As mentioned in the background art, existing image measurement methods need to be further improved. This will now be analyzed and explained in conjunction with specific embodiments.

[0032] Currently, the cut layer is subject to interference from the preceding layer during AEI (Post-Etch Inspection) measurement. Consequently, the machine cannot accurately grasp the measurement frame position, resulting in inaccurate measurement results that require manual processing. Furthermore, as critical dimensions decrease, a large number of graphic patterns need to be measured for confirmation, leading to a large amount of manual processing and a very time-consuming process.

[0033] Specifically, when measuring the cut layer during the AEI stage (post-etch inspection), the cut layer must be measured. However, this step may interfere with some previously formed graphic patterns, causing the machine's measurement position to shift. The measured position is not on the graphic pattern, resulting in inaccurate measurement values. A large amount of data needs to be remeasured, which is very time-consuming.

[0034] In order to solve the above problems, the present invention provides an overlay accuracy error detection method, storage medium and terminal. The initial design layout is a design pattern, and the initial measurement layout is an actual pattern. Due to the presence of a large number of interference patterns on the initial measurement layout, the positioning of the measurement frame is offset, while the pattern on the initial design layout is relatively regular. By obtaining a first measurement pattern on the initial design layout and combining the first measurement pattern with a second transition pattern, a valid pattern corresponding to the first measurement pattern and the position of the valid pattern in the second transition layout are obtained. Since the valid pattern is the detection object of the overlay accuracy error detection, the position of the valid pattern corresponds to the position of the measurement frame. Therefore, the second measurement area is obtained, that is, the position of the measurement frame in the initial measurement layout is determined, thereby improving the accuracy and efficiency of subsequent overlay accuracy error detection. In addition, in the technical solution of the present invention, before obtaining the first measurement pattern and the valid pattern, image processing is performed on the initial design layout and the initial measurement layout, so that the first measurement pattern and the valid pattern are clearer, further improving the accuracy and efficiency of overlay accuracy error detection.

[0035] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Figure 1 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 1 .

[0037] Please refer to Figure 1 , the overlay accuracy error detection method includes:

[0038] S1: Obtain an initial design layout, wherein the initial design layout includes a plurality of design graphics;

[0039] S2: obtaining an initial measurement layout through the initial design layout, wherein the initial measurement layout includes a plurality of actual graphics corresponding to the design graphics;

[0040] S3: performing a first image processing on the initial design layout to obtain a first transition layout, wherein the first transition layout includes a plurality of first transition graphics corresponding to the plurality of design graphics;

[0041] S4: setting a first measurement area in the first transition layout, and obtaining a first transition pattern in the first measurement area as a first measurement pattern, wherein the first measurement pattern has position information in the first transition layout;

[0042] S5: performing a second image processing on the initial measurement layout to obtain a second transition layout, where the second transition layout includes a plurality of second transition graphics corresponding to the plurality of actual graphics;

[0043] S6: extracting a valid pattern corresponding to the first measurement pattern from a plurality of second transition patterns according to the position information of the measurement pattern;

[0044] S7: Acquire a second measurement area in the initial measurement layout according to the position of the valid pattern.

[0045] In the above scheme, the initial design layout is the design graphic, and the initial measurement layout is the actual graphic. Since there are a large number of interference graphics on the initial measurement layout, the positioning of the measurement frame is offset, and the graphics on the initial design layout are relatively regular. By obtaining the first measurement graphic on the initial design layout and combining the first measurement graphic with the second transition graphic, the valid graphic corresponding to the first measurement graphic and the position of the valid graphic in the second transition layout are obtained. Since the valid graphic is the detection object of the overlay accuracy error detection, the position of the valid graphic corresponds to the position of the measurement frame, and thus the second measurement area is obtained, that is, the position of the measurement frame in the initial measurement layout is determined, thereby improving the accuracy and efficiency of subsequent overlay accuracy error detection; in addition, in the technical solution of the present invention, before obtaining the first measurement graphic and the valid graphic, the initial design layout and the initial measurement layout are image processed, so that the first measurement graphic and the valid graphic are clearer, further improving the accuracy and efficiency of the overlay accuracy error detection.

[0046] Figure 2 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 2 .

[0047] Please refer to Figure 2 The first image processing method in step S3 includes:

[0048] S31: first perform channel extraction processing on the design graphic;

[0049] S32: After the channel extraction process, the design pattern is binarized.

[0050] The channel extraction process is used to perform grayscale processing on the design graphic.

[0051] The binarization process is used to perform black and white processing on the design graphic to obtain a first transitional layout with a clear outline.

[0052] Figure 3 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 3 .

[0053] Please refer to Figure 3 The second image processing method in step S5 includes:

[0054] S53: Perform morphological opening operation on the actual graphics.

[0055] The morphological opening operation is used to remove the interference graphics in the actual graphics to obtain the second transitional layout.

[0056] The second image processing method further includes:

[0057] S51: before performing morphological opening operation on the actual image, performing median filtering denoising on the actual image;

[0058] S52: performing binarization processing after the median filtering denoising processing.

[0059] The median filter denoising process is used to set the pixel points in the actual image to the median of the grayscale values ​​of all pixels to denoise the actual image.

[0060] The binarization process is used to perform black and white processing on the actual pattern to obtain an initial measurement layout with clear outlines.

[0061] In the above scheme, the initial design layout is first subjected to channel extraction processing and then to binarization processing, so that the initial design layout is grayscaled and the fine line interference in the initial design layout is removed to obtain a first transition figure with a clear outline, thereby improving the accuracy of subsequent positioning of the first measurement area and the positioning of the first measurement figure.

[0062] Figure 4 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 4 .

[0063] Please refer to Figure 4 , the method of performing morphological opening operation on the initial measurement layout includes:

[0064] S531: performing an etching process on the actual pattern, and then performing an expansion process on the actual pattern to obtain a first initial measurement layout;

[0065] S532: Performing contour extraction processing on the first initial measurement layout;

[0066] S533: After the contour extraction process, a minimum area screening process is performed on the contour of the actual graphic.

[0067] The contour extraction process is used to obtain the contour of the actual graphic.

[0068] The minimum area screening process is used to remove invalid areas in the outline of the actual graphic to obtain a second transition layout.

[0069] In this embodiment, the etching process and the dilation process are characterized as virtual operations on the measurement layout.

[0070] In the above scheme, the technical solution of the present invention obtains an initial measurement layout with clear contours by performing median filtering denoising and binarization processing on the initial measurement layout, and uses morphological opening operation processing to first erode the initial measurement layout and then perform dilation processing to disconnect or remove the fine lines in the interference pattern, thereby further achieving the clarification of the initial measurement layout and improving the accuracy of the second measurement area positioning and overlay accuracy test.

[0071] Figure 5 This is a flow chart of a method for detecting overlay accuracy errors in one embodiment of the present invention. Figure 5 .

[0072] Please refer to Figure 5 The method of obtaining the second measurement area in the initial measurement layout according to the position of the valid pattern in step S7 includes:

[0073] S71: After obtaining the position of the effective pattern, locate the center position of the initial measurement layout according to the position of the effective pattern;

[0074] S72: Based on the center position and the second measurement area, calibrate the position of the measurement frame in the initial measurement layout.

[0075] The position of the corrected measurement frame is axially symmetrically distributed about the center position, and the position of the second measurement area corresponds to the position of the corrected measurement frame.

[0076] The method of extracting a valid pattern corresponding to the first measurement pattern from a plurality of second transition patterns in step S6 includes:

[0077] S61: extracting an overlapping portion of the first measurement pattern and the second transition pattern, wherein the overlapping portion is a valid pattern in the second transition pattern.

[0078] In the above scheme, the actual pattern in the second measurement area is used as the second measurement pattern, and the second measurement pattern is tested for overlay accuracy. Since the second measurement pattern corresponds to the first measurement pattern, and the first measurement pattern is obtained from the design pattern, the accuracy of the position positioning of the second measurement area is achieved, and the accuracy and efficiency of subsequent overlay accuracy error detection are improved.

[0079] In this embodiment, after step S7, the method further includes: acquiring an actual pattern in the second measurement area as a second measurement pattern; and performing an overlay accuracy test on the second measurement pattern.

[0080] The following combination Figures 6 to 11 Describe the above steps:

[0081] Figure 6This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 1 .

[0082] Please refer to FIG. 6 , the first transition layout 800 includes a first transition pattern 801 , a first measurement area 802 , and a first measurement pattern 8021 located in the first measurement area 802 .

[0083] Since the design graphics in the initial design layout are in color, while the measurement graphics are in black and white, the initial design layout (not shown in the figure) is subjected to RGB channel extraction processing to remove the colors in the initial design layout. Then, the initial design layout (not shown in the figure) is binarized to clarify the outline of the design graphics, thereby obtaining a first transition layout 800. Among them, the first transition graphic 801 in the first transition layout 800 is a graphic with a clear outline.

[0084] Figure 7 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 2 .

[0085] Please Figure 6 Based on reference Figure 7 , the first transition layout 800 includes a first measurement graphic 8021 located in the first measurement area 802.

[0086] A first measurement area 802 is set in the first transition layout 800 , and a first transition graphic 801 in the first measurement area 802 is obtained as a first measurement graphic 8021 .

[0087] Position information of the first measurement pattern 8021 in the first transition layout 800 is the same as position information of the first measurement area 802 in the first transition layout 800 .

[0088] Figure 8 This is a schematic diagram of the structure of the initial measurement layout in one embodiment of the present invention. Figure 1 .

[0089] Figure 9 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 1 .

[0090] Please refer to Figure 8 as well as Figure 9 The initial measurement layout 900 includes: an actual pattern 901, an interference pattern 902 and a measurement frame 904 in the initial measurement layout, and the second transition layout 1000 includes a second transition pattern 1001 and a second measurement area 1002.

[0091] Because the initial measurement layout 900 includes a large number of interference patterns 902 and interference thin lines, the position of the measurement frame 904 in the initial measurement layout is inaccurate. Therefore, the initial measurement layout 900 is subjected to median filtering and denoising processing to remove the interference patterns 902 in the initial measurement layout 900. The initial measurement layout 900 is then binarized to clarify the outline of the initial measurement layout 900.

[0092] Secondly, a morphological opening operation is performed on the initial measurement layout 900. Specifically, the actual graphic 901 is first corroded and then dilated. That is, the lines of the actual graphic 901 are first corroded to remove interfering fine lines, and then the lines of the actual graphic 901 are dilated to clarify the outline of the actual graphic 901 and extract the outline of the actual graphic 901.

[0093] Finally, after the contour extraction process, a minimum area screening process is performed on the contour of the actual graphic 901 to remove invalid areas in the contour of the actual graphic 901 and obtain a second transitional layout 1000 .

[0094] Figure 10 This is a schematic diagram of the structure of the first transition diagram in one embodiment of the present invention. Figure 2 .

[0095] Please refer to Figure 10 The second transition layout 1000 also includes a valid graphic 10021 located in the second measurement area 1002.

[0096] By extracting the overlapping portion of the first measurement pattern 8021 and the second transition pattern 1001 , the overlapping portion is a valid pattern 10021 in the second transition pattern 1001 .

[0097] Figure 11 This is a schematic diagram of the structure of the initial measurement layout in one embodiment of the present invention. Figure 2 .

[0098] Please Figure 9 、 Figure 10 Based on reference Figure 11 The initial measurement layout 900 also includes a corrected measurement frame 905 and a second measurement pattern 9051 located in the corrected measurement frame.

[0099] After obtaining the position of the valid pattern 10021, the center position of the initial measurement layout 900 (i.e., the cross in the figure) is located according to the position of the valid pattern 10021. The position of the measurement frame 904 in the initial measurement layout is corrected at the center position and the second measurement area 1002. The position of the corrected measurement frame 905 is axially symmetrical about the center position. The position of the second measurement area 1002 corresponds to the position of the corrected measurement frame 905, and the second measurement pattern 9051 within the corrected measurement frame 905 is obtained.

[0100] Correspondingly, the technical solution of the present invention further provides a storage medium on which computer instructions are stored, and when the computer instructions are executed, the steps of the above-mentioned overlay accuracy error detection method are executed.

[0101] Correspondingly, the technical solution of the present invention also provides a terminal, including a memory and a processor, wherein the memory stores computer instructions that can be run on the processor, and the processor executes the steps of the above-mentioned overlay accuracy error detection method when running the computer instructions.

[0102] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for detecting overlay accuracy error, characterized in that: include: Obtaining an initial design layout, wherein the initial design layout includes a plurality of design graphics; Obtaining an initial measurement layout through the initial design layout, wherein the initial measurement layout includes a plurality of actual graphics corresponding to the design graphics; Performing a first image processing on the initial design layout to obtain a first transition layout, wherein the first transition layout includes a plurality of first transition graphics corresponding to the plurality of design graphics; Setting a first measurement area in the first transition layout, and acquiring a first transition pattern in the first measurement area as a first measurement pattern, wherein the first measurement pattern has position information in the first transition layout; Performing a second image processing on the initial measurement layout to obtain a second transition layout, wherein the second transition layout includes a plurality of second transition graphics corresponding to the plurality of actual graphics; extracting a valid pattern corresponding to the first measurement pattern from a plurality of second transition patterns according to position information of the measurement pattern; According to the position of the effective pattern, a second measurement area is obtained in the initial measurement layout.

2. The overlay accuracy error detection method according to claim 1, wherein: The first image processing method includes: first performing channel extraction processing on the design graphic, and the channel extraction processing is used to grayscale the design graphic; and after the channel extraction processing, performing binarization processing on the design graphic, and the binarization processing is used to black and white the design graphic to obtain a first transitional layout with clear contours.

3. The overlay accuracy error detection method according to claim 1, wherein: The second image processing method includes: performing morphological opening operation on the actual graphic, wherein the morphological opening operation is used to remove interference graphics in the actual graphic and obtain a second transitional layout.

4. The overlay accuracy error detection method according to claim 3, wherein: The method for performing morphological opening operation on the initial measurement layout includes: first performing corrosion processing on the actual graphic, and then performing dilation processing after the corrosion processing to obtain a first initial measurement layout; performing contour extraction processing on the first initial measurement layout, wherein the contour extraction processing is used to obtain the contour of the actual graphic; after the contour extraction processing, performing minimum area screening processing on the contour of the actual graphic, wherein the minimum area screening processing is used to remove invalid areas in the contour of the actual graphic, and obtain a second transition layout.

5. The overlay accuracy error detection method according to claim 3, wherein: The second image processing method also includes: before performing morphological opening operation on the actual graphic, performing median filtering denoising on the actual graphic, the median filtering denoising is used to set the pixels in the actual graphic to the median of the grayscale values ​​of all pixels to denoise the actual graphic; and performing binarization after the median filtering denoising, the binarization is used to convert the actual graphic into black and white to obtain an initial measurement layout with clear contours.

6. The overlay accuracy error detection method according to claim 1, wherein: The method for obtaining a second measurement area in the initial measurement layout according to the position of the effective pattern includes: after obtaining the position of the effective pattern, locating the center position of the initial measurement layout according to the position of the effective pattern; based on the center position and the second measurement area, correcting the position of the measurement frame in the initial measurement layout, wherein the position of the corrected measurement frame is axially symmetrical with respect to the center position, and the position of the second measurement area corresponds to the position of the corrected measurement frame.

7. The overlay accuracy error detection method according to claim 1, wherein: The method of extracting a valid pattern corresponding to the first measurement pattern from a plurality of second transition patterns includes: extracting an overlapping portion of the first measurement pattern and the second transition pattern, wherein the overlapping portion is a valid pattern in the second transition pattern.

8. The overlay accuracy error detection method according to claim 1, wherein: Also includes: Acquire an actual pattern within the second measurement area as a second measurement pattern; An overlay accuracy test is performed on the second measurement pattern.

9. A storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed, the steps of the method according to any one of claims 1 to 8 are executed.

10. A terminal comprising a memory and a processor, wherein the memory stores computer instructions that can be executed on the processor, characterized in that: When the processor executes the computer instructions, the steps of the method according to any one of claims 1 to 8 are performed.

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