Graph correction method, storage medium and terminal

Abstract

The invention discloses a graph correction method, a storage medium and a terminal, and the method comprises the steps: providing a to-be-corrected layout which comprises a plurality of to-be-corrected graphs; the multiple to-be-corrected graphs are grouped, one group comprises at least one to-be-corrected graph, and the multiple to-be-corrected graphs in one group are the same; segmenting the contour of the to-be-corrected graph in each group into a plurality of line segments; the line segments in the group are classified, a plurality of types of line segments are obtained, and the line segments with the same positions in the to-be-corrected graphs in the group are the same type of line segments; providing a correction model; one type of line segments in each group are moved at a time, optical proximity effect correction is carried out on the to-be-corrected graph according to the correction model until a correction layout is obtained, and the correction layout comprises a plurality of correction graphs. The number of iterations of the correction process is reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular, to a method for pattern correction, a storage medium, and a terminal. Background Art

[0002] With the further advancement of semiconductor technology nodes, semiconductor manufacturing processes are currently approaching nodes of 5nm and above. Optical Proximity Correction (OPC) is an important technical means in semiconductor manufacturing technology, and the impact of pattern edge placement error during the optical proximity correction process on device performance is increasing.

[0003] As the size of semiconductor devices shrinks, the difficulty of mask manufacturing further increases. Therefore, the process of optical proximity correction needs to be continuously optimized to adapt to the manufacturing process of semiconductor devices. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a method for pattern correction, a storage medium, and a terminal to reduce the difficulty of mask manufacturing and improve the accuracy of optical proximity correction.

[0005] To solve the above technical problem, the technical solution of the present invention provides a method for pattern correction, including: providing a layout to be corrected, where the layout to be corrected includes a plurality of patterns to be corrected; grouping the plurality of patterns to be corrected, with at least one pattern to be corrected in one group, and the plurality of patterns to be corrected in one group being the same; dividing the contours of the patterns to be corrected in each group into a plurality of line segments; classifying the plurality of line segments in the group to obtain a plurality of types of line segments, and the line segments in the same position in each pattern to be corrected in the group being the same type of line segment; providing a correction model; moving one type of line segment in each group once, and performing optical proximity correction on the pattern to be corrected according to the correction model until a corrected layout is obtained, where the corrected layout includes a plurality of corrected patterns.

[0006] Optionally, moving one type of line segment in each group once and performing optical proximity correction on the pattern to be corrected according to the correction model, the correction process includes: selecting one type of line segment from each group and moving the selected one type of line segment in each group; after moving the selected one type of line segment in each group, performing simulated exposure on the pattern to be corrected to obtain a simulated exposure pattern; obtaining the average edge placement error between the simulated exposure pattern and the target pattern; determining whether the average edge placement error is within a preset range; if the average edge placement error is within the preset range, obtaining a corrected pattern; if the average edge placement error is not within the preset range, repeating the above steps until the average edge placement error is within the preset range to obtain a corrected pattern.

[0007] Optionally, the method of selecting a type of line segment from each group and moving the selected type of line segment in each group includes: before moving the line segment, performing simulated exposure on a plurality of the to-be-corrected graphics to obtain an initial simulated exposure graphic; obtaining the average edge placement error between the initial simulated exposure graphic and the target graphic; selecting a type of line segment from each group, and moving the selected type of line segment in each group according to the average edge placement error of the selected type of line segment.

[0008] Optionally, selecting a type of line segment from each group includes: selecting the type of line segment with the largest edge placement error for movement.

[0009] Optionally, when the number of iterations of the correction process is multiple, when selecting multiple times, several types of the line segments can be selected repeatedly.

[0010] Optionally, selecting a type of line segment from each group includes: randomly selecting a type of line segment for movement.

[0011] Optionally, when the number of iterations of the correction process is multiple, several types of the line segments are not selected repeatedly.

[0012] Optionally, the multiple to-be-corrected graphics in a group are the same, including: the sizes of the multiple to-be-corrected graphics in the group in the first direction are the same, the sizes of the multiple to-be-corrected graphics in the group in the second direction are the same, the areas of the multiple to-be-corrected graphics in the group are the same, and the first direction is perpendicular to the second direction.

[0013] Optionally, the segmentation methods of the contours of the to-be-corrected graphics in the group are the same, the number of line segments obtained by segmenting the contours of the to-be-corrected graphics in the group is the same, and the positions of several line segments of the to-be-corrected graphics in the group correspond one by one.

[0014] Correspondingly, the technical solution of the present invention also provides a storage medium, on which computer instructions are stored, characterized in that when the computer instructions run, they execute the steps of the above method.

[0015] Correspondingly, the technical solution of the present invention also provides a terminal, including a memory and a processor, where computer instructions capable of running on the processor are stored on the memory, characterized in that when the processor runs the computer instructions, it executes the steps of the above method.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0017] The graphic correction method of the present invention classifies several line segments in a group to obtain several types of line segments, and only selects one type of line segment of the graphic to be corrected in the group for movement at a time until the corrected layout is obtained. On the one hand, this process reduces the number of iterations in the optical proximity correction process, thereby reducing the calculation amount and complexity of the correction model; on the other hand, this process makes the edge placement error easy to converge, and it is not easy to have a large size drop in some corner areas, which is convenient for the subsequent corrected graphic to be made on the photoresist through a mask, and the accuracy of the corner area is better controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 and Figure 2 are the schematic flowcharts of the graphic correction method in the embodiments of the present invention;

[0019] Figures 3 to 6 are the schematic structural diagrams of the graphic correction process in the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] As described in the background art, the process of optical proximity effect correction needs to be further optimized to adapt to the manufacturing process of semiconductor devices.

[0021] Specifically, the graphic correction process includes: providing a layout to be corrected, where the layout to be corrected includes several graphics to be corrected; generating auxiliary graphics around several of the graphics to be corrected based on the auxiliary graphic generation rules; providing a correction model; dividing the contour of the graphic to be corrected into several line segments; providing a correction model; performing optical proximity effect correction on the graphic to be corrected according to the correction model, and after multiple iterations, obtaining a corrected layout, where the corrected layout includes several corrected graphics.

[0022] The process of performing optical proximity effect correction on the graphic to be corrected according to the correction model includes: performing simulated exposure on the graphic to be corrected to obtain a simulated exposure graphic; obtaining the edge placement error between the simulated exposure graphic and the target graphic; determining whether the edge placement error is within a preset range; if the edge placement error is not within the preset range, moving several of the line segments according to the edge placement error; performing simulated exposure on the graphic to be corrected after moving several of the line segments to obtain a simulated exposure graphic; determining whether the edge placement error is within the preset range, if the edge placement error is within the preset range, then obtaining a corrected graphic; if the edge placement error is not within the preset range, then repeating the above steps until a corrected graphic is obtained.

[0023] In one embodiment, when moving several of the line segments according to the edge placement error, the several line segments move completely automatically according to the correction model. The disadvantage of this process is that the edge placement error (EPE) is large, the computational complexity is huge, and the number of movements is large. It is difficult for the edge placement error to converge and it is difficult to control the edge placement error within a small range.

[0024] In another embodiment, when moving several of the line segments according to the edge placement error, the several line segments move according to the settings of the target control added in the correction model. The advantage of this process is that it can improve the convergence process of the edge placement error and can control the edge placement error within a small range; the disadvantage is that due to fast convergence, the size difference is large in some corner regions, and it is difficult for the corrected modified pattern to be exposed on the photoresist through the mask, and the accuracy of the corner regions is difficult to control, and corner rounding is likely to occur.

[0025] To solve the above problems, the technical solution of the present invention provides a pattern correction method, a storage medium, and a terminal. The pattern correction method classifies several line segments in a group to obtain several types of line segments, and only selects one type of line segment of the pattern to be corrected in the group for movement at a time until the corrected layout is obtained. On the one hand, this process reduces the number of iterations in the optical proximity correction process, thereby reducing the computational complexity and computational amount of the correction model; on the other hand, this process makes the edge placement error easy to converge, and it is not easy to have a large size difference in some corner regions, which is convenient for the subsequent corrected pattern to be made on the photoresist through the mask, and the accuracy of the corner regions is better controlled.

[0026] To make the above objects, features, and beneficial effects of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0027] Figure 1 and Figure 2 are the schematic flowcharts of the pattern correction method in the embodiments of the present invention; Figures 3 to 6 is the schematic structural diagram of the pattern correction process in the embodiments of the present invention.

[0028] Please refer to Figure 1 , the pattern correction method includes:

[0029] Step S10: Provide a layout to be corrected, and the layout to be corrected includes several patterns to be corrected;

[0030] Step S20: Group several of the patterns to be corrected, where at least one pattern to be corrected is included in one group, and the multiple patterns to be corrected in one group are the same;

[0031] Step S30: Divide the contour of the to-be-corrected graphics in each group into several line segments;

[0032] Step S40: Classify the several line segments within the group to obtain several classes of line segments. The line segments in the same position in each to-be-corrected graphic within the group belong to the same class of line segments;

[0033] Step S50: Provide a correction model;

[0034] Step S60: Move one class of line segments in each group at a time, and perform optical proximity effect correction on the to-be-corrected graphics according to the correction model until a corrected layout is obtained. The corrected layout includes several corrected graphics.

[0035] For the graphic correction method, classify the several line segments within the group to obtain several classes of line segments, and only select one class of line segments of the to-be-corrected graphics within the group for movement at a time until a corrected layout is obtained. On the one hand, this process reduces the number of iterations in the optical proximity correction process, thereby reducing the calculation amount and calculation complexity of the correction model; on the other hand, this process makes the edge placement error easy to converge, and it is not easy to have a large size drop in some corner areas, which is convenient for the subsequent corrected graphics to be made on the photoresist through the mask plate, and the accuracy of the corner area is better controlled.

[0036] Next, analyze and explain each step.

[0037] Please refer to Figure 3 Continue to refer to Figure 1 , and execute Step S10: Provide a to-be-corrected layout 100, where the to-be-corrected layout includes several to-be-corrected graphics.

[0038] The to-be-corrected layout 100 is an initial design graphic. After optical proximity correction, the to-be-corrected layout 100 obtains a corrected layout, and the corrected layout is the graphic that will be made on the mask plate and form a patterned layer later.

[0039] Several of the to-be-corrected graphics have dimensions in a first direction X and a second direction Y, and the first direction X is perpendicular to the second direction Y.

[0040] Please continue to refer to Figure 1 , and execute Step S20: Group several of the to-be-corrected graphics. At least one to-be-corrected graphic is included in one group, and the multiple to-be-corrected graphics in one group are the same.

[0041] That the multiple to-be-corrected graphics in one group are the same includes: the dimensions of the multiple to-be-corrected graphics in the group in the first direction X are the same, the dimensions of the multiple to-be-corrected graphics in the group in the second direction Y are the same, and the areas of the multiple to-be-corrected graphics in the group are the same, and the first direction X is perpendicular to the second direction Y.

[0042] Please refer to Figure 4 , Figure 4 , which schematically divides several graphics to be corrected into two groups. The first group includes the first graphic to be corrected 101. The dimensions of multiple first graphics to be corrected 101 are the same in the first direction X, the dimensions are the same in the second direction Y, and the areas of multiple first graphics to be corrected 101 are the same. The second group includes the second graphic to be corrected 102. The dimensions of multiple second graphics to be corrected 102 are the same in the first direction X, the dimensions are the same in the second direction Y, and the areas of multiple second graphics to be corrected 102 are the same.

[0043] Please continue to refer to Figure 4 , and based on the auxiliary graphic generation rule, auxiliary graphics 103 are generated around several of the graphics to be corrected.

[0044] The auxiliary graphics 103 are some very small graphics, which are placed around the graphics to be corrected to increase the subsequent exposure density of the graphics to be corrected and increase the process window of exposure.

[0045] The minimum dimension of the auxiliary graphics 103 is smaller than the resolution of the lithography machine.

[0046] The auxiliary graphic generation rule is a rule for pre-designed placement of auxiliary graphics 103 around the graphics to be corrected, including the mask making constraints (abbreviated as mrc). The mask making constraints include: the distance between graphics shall not be less than a preset minimum distance.

[0047] Figure 4 The auxiliary graphics 103 described in are distributed around the first graphic to be corrected 101 and around the second graphic to be corrected 102.

[0048] Please combine with Figure 5 Continue to refer to Figure 1 , and perform step S30: divide the contours of the graphics to be corrected within each group into several line segments.

[0049] The segmentation methods of the contours of the graphics to be corrected within each group are the same, the number of line segments for the contour segmentation of the graphics to be corrected within each group is the same, and the positions of several line segments of the graphics to be corrected within each group correspond one by one.

[0050] Figure 5As shown in [reference], the contour of multiple first graphics to be corrected 101 in the first group is divided into several line segments. The division methods of the contours of multiple first graphics to be corrected 101 are the same, and the number of line segments obtained by dividing the contours of multiple first graphics to be corrected 101 is the same. The contour of multiple second graphics to be corrected 102 in the second group is divided into several line segments. The division methods of the contours of multiple second graphics to be corrected 102 are the same, and the number of line segments obtained by dividing the contours of multiple second graphics to be corrected 102 is the same.

[0051] Please refer to Figure 5 Continue to refer to Figure 1 , and perform step S40: Classify several line segments within the group to obtain several types of line segments. Line segments with the same position in each graphic to be corrected within the group are of the same type.

[0052] Since the sizes of multiple graphics to be corrected within the group are the same in the first direction X, the sizes of multiple graphics to be corrected within the group are the same in the second direction Y, the areas of multiple graphics to be corrected within the group are the same, the positions of several line segments of each graphic to be corrected within the group correspond one by one, and line segments with the same position in each graphic to be corrected within the group are of the same type, that is, line segments at corresponding positions of the contours of each graphic to be corrected within the group are of the same type.

[0053] Figure 5 As shown in [reference], among the several line segments obtained by dividing the contour of multiple first graphics to be corrected 101 in the first group, the first line segment 120 is a type of line segment in the first group; among the several line segments obtained by dividing the contour of multiple second graphics to be corrected 102 in the second group, the second line segment 121 is a type of line segment in the second group.

[0054] Please continue to refer to Figure 1 , and perform step S50: Provide a correction model.

[0055] The correction model is a model for performing optical proximity effect correction.

[0056] Please continue to refer to Figure 1 , and perform step S60: Move a type of line segment in each group once, and perform optical proximity effect correction on the graphic to be corrected according to the correction model until a corrected layout is obtained. The corrected layout includes several corrected graphics.

[0057] Please continue to refer to Figure 5 in combination with Figure 2 . In this embodiment, a type of line segment in each group is moved once, and optical proximity effect correction is performed on the graphic to be corrected according to the correction model. The correction process includes:

[0058] Step S601: Select a type of line segment from each group and move the selected type of line segment in each group.

[0059] Step S602: After moving a selected type of line segments in each group, perform simulated exposure on the to-be-corrected pattern to obtain a simulated exposure pattern.

[0060] Step S603: Obtain the average edge placement error between the simulated exposure pattern and the target pattern.

[0061] Step S604: Determine whether the average edge placement error is within a preset range.

[0062] Step S605: If the average edge placement error is within the preset range, obtain the corrected pattern.

[0063] Step S606: If the average edge placement error is not within the preset range, repeat the above steps until the average edge placement error is within the preset range, and then obtain the corrected pattern.

[0064] In this embodiment, in step S601, the method of selecting a type of line segments from each group and moving the selected type of line segments in each group includes: before moving the line segments, perform simulated exposure on a plurality of the to-be-corrected patterns to obtain an initial simulated exposure pattern; obtain the average edge placement error between the initial simulated exposure pattern and the target pattern; select a type of line segments from each group, and move the selected type of line segments in each group according to the edge placement error of the selected type of line segments.

[0065] The target pattern is a pattern that needs to be exposed onto the photoresist layer through a mask in the subsequent process, and the target pattern is a pattern for forming a semiconductor structure on a wafer in the subsequent process.

[0066] It should be noted that after obtaining the average edge placement error between the initial simulated exposure pattern and the target pattern, it further includes: determining whether the average edge placement error between the initial simulated exposure pattern and the target pattern is within the preset range. If the average edge placement error between the initial simulated exposure pattern and the target pattern is within the preset range, there is no need to correct the to-be-corrected pattern; when the average edge placement error between the initial simulated exposure pattern and the target pattern is not within the preset range, select a type of line segments from each group and move the selected type of line segments in each group.

[0067] The average edge placement error is: the average value of the edge placement errors of a plurality of line segments obtained by dividing the contour of the to-be-corrected pattern, and an edge placement error can be obtained for each line segment.

[0068] Select a type of line segments from each group and move the selected type of line segments in each group, refer to Figure 5As shown in the figure, select the first line segments 120 of multiple first graphics to be corrected 101 in the first group, and move the first line segments 120 according to the edge placement error of the first line segments 120; select the second line segments 121 of multiple second graphics to be corrected 102 in the second group, and move the second line segments 121 according to the edge placement error of the second line segments 121.

[0069] In one embodiment, select a type of line segment from each group, including: selecting the type of line segment with the largest edge placement error for movement. That is, when selecting a type of line segment from each group for the first time, after obtaining the average edge placement error between the initial simulated exposure pattern and the target pattern, select the type of line segment with the largest edge placement error for movement; after movement, perform simulated exposure on the graphics to be corrected again, obtain the average edge placement error between the simulated exposure pattern and the target pattern, and continue to select the type of line segment with the largest edge placement error for movement. Selecting the type of line segment with the largest edge placement error for movement can minimize the number of iterations as much as possible, so that the average edge placement error meets the preset range.

[0070] In another embodiment, select a type of line segment from each group, including: randomly selecting a type of line segment for movement.

[0071] In one embodiment, when the number of iterations of the correction process is multiple, when selecting multiple times, several types of the line segments can be selected repeatedly. That is, under some rules for selecting line segments, for example, when selecting the type of line segment with the largest edge placement error for movement, the selected line segments within the group may be selected repeatedly.

[0072] In another embodiment, when the number of iterations of the correction process is multiple, several types of the line segments are not selected repeatedly. That is, different types of line segments within the group are selected each time.

[0073] Please refer to Figure 6 , in step S606: If the average edge placement error is not within the preset range, repeat the above steps until the average edge placement error is within the preset range to obtain the corrected pattern.

[0074] Figure 6 As shown in the figure, repeating the above steps includes: step S601: Select the third line segments 122 of multiple first graphics to be corrected 101 in the first group, and move the third line segments 122 according to the edge placement error of the third line segments 122; select the fourth line segments 123 of multiple second graphics to be corrected 102 in the second group, and move the fourth line segments 123 according to the edge placement error of the fourth line segments 123.

[0075] Then continue the process from S602 to S606 until the average edge placement error is within the preset range, then stop the correction iteration to obtain the corrected layout.

[0076] In this embodiment, if the average edge placement error is within a preset range, the correction iteration is stopped, and a corrected layout is obtained. The corrected layout includes a number of corrected patterns, and the corrected patterns correspond to the patterns to be corrected one by one.

[0077] The corrected layout is the pattern that needs to be made on the mask plate subsequently. Then, the pattern is exposed onto the photoresist layer through the mask plate, and the pattern on the photoresist layer is the same as or infinitely close to the target pattern.

[0078] For the pattern correction method, a number of line segments in the group are classified to obtain a number of types of line segments. Only one type of line segment of the pattern to be corrected in the group is selected for movement each time until the corrected layout is obtained. On the one hand, this process reduces the number of iterations in the optical proximity correction process, thereby reducing the calculation amount and calculation complexity of the correction model; on the other hand, this process makes the edge placement error easy to converge, and it is not easy to have a large size drop in some corner regions, which is convenient for the subsequent corrected pattern to be made on the photoresist through the mask plate, and the accuracy of the corner region is better controlled.

[0079] Correspondingly, an embodiment of the present invention further provides a storage medium, on which computer instructions are stored, and characterized in that when the computer instructions run, they execute the steps as Figure 1 and Figure 2 the method described above.

[0080] Correspondingly, an embodiment of the present invention further provides a terminal, including a memory and a processor. The memory stores computer instructions that can run on the processor, and characterized in that when the processor runs the computer instructions, it executes the steps as Figure 1 and Figure 2 the method described above.

[0081] 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 protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A method for graphic correction, characterized in that, it includes: providing a layout to be corrected, where the layout to be corrected includes several graphics to be corrected; grouping the several graphics to be corrected, with at least one graphic to be corrected in one group, and the multiple graphics to be corrected in one group being the same; dividing the contours of the graphics to be corrected in each group into several line segments; classifying the several line segments in the group to obtain several types of line segments, and the line segments in the same position in each graphic to be corrected in the group being the same type of line segment; providing a correction model; moving one type of line segment in each group once, and performing optical proximity effect correction on the graphics to be corrected according to the correction model until a corrected layout is obtained, where the corrected layout includes several corrected graphics.

2. The method for graphic correction according to claim 1, characterized in that, moving one type of line segment in each group once, and performing optical proximity effect correction on the graphics to be corrected according to the correction model, and the correction process includes: selecting one type of line segment from each group and moving the selected one type of line segment in each group; after moving the selected one type of line segment in each group, performing simulated exposure on the graphics to be corrected to obtain a simulated exposure graphic; obtaining the average edge placement error between the simulated exposure graphic and the target graphic; determining whether the average edge placement error is within a preset range; if the average edge placement error is within the preset range, obtaining the corrected graphic; if the average edge placement error is not within the preset range, repeating the above steps until the average edge placement error is within the preset range to obtain the corrected graphic.

3. The method for graphic correction according to claim 2, characterized in that, The method of selecting one type of line segment from each group and moving the selected one type of line segment in each group includes: before moving the line segment, performing simulated exposure on the several graphics to be corrected to obtain an initial simulated exposure graphic; obtaining the average edge placement error between the initial simulated exposure graphic and the target graphic; selecting one type of line segment from each group and moving the selected one type of line segment in each group according to the average edge placement error of the selected one type of line segment.

4. The method for graphic correction according to claim 2, characterized in that, selecting one type of line segment from each group includes: selecting the type of line segment with the largest edge placement error for movement.

5. The method for graphic correction according to claim 2, characterized in that, when the number of iterations of the correction process is multiple times, when selecting multiple times, several types of the line segments can be repeatedly selected.

6. The method for graphic correction according to claim 2, characterized in that, selecting one type of line segment from each group includes: randomly selecting one type of line segment for movement.

7. The method for graphic correction according to claim 2, characterized in that, when the number of iterations of the correction process is multiple times, several types of the line segments are not repeatedly selected.

8. The method for graphic correction according to claim 1, characterized in that, Multiple graphics to be corrected within a group are the same, including: the dimensions of multiple graphics to be corrected within the group are the same in the first direction, the dimensions of multiple graphics to be corrected within the group are the same in the second direction, the areas of multiple graphics to be corrected within the group are the same, and the first direction is perpendicular to the second direction.

9. The graphic correction method according to claim 8, characterized in that the segmentation methods of the contours of each graphic to be corrected within the group are the same, the number of line segments for contour segmentation of each graphic to be corrected within the group is the same, and the positions of several line segments of each graphic to be corrected within the group correspond one by one.

10. A storage medium, on which computer instructions are stored, characterized in that when the computer instructions run, they execute the steps of the method according to any one of claims 1 to 9.

11. A terminal, comprising a memory and a processor, and computer instructions capable of running on the processor are stored on the memory, characterized in that when the processor runs the computer instructions, it executes the steps of the method according to any one of claims 1 to 9.

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