Graphics correction method

Abstract

A pattern correction method includes: providing a layout to be corrected, the layout to be corrected including a plurality of patterns to be corrected; providing a first target layout, the first target layout including a plurality of first target patterns corresponding one-to-one with the plurality of patterns to be corrected; performing a first optical proximity correction on the layout to be corrected to obtain a first correction layout, the first correction layout including a plurality of first correction patterns corresponding to the patterns to be corrected; obtaining first edge placement errors of the plurality of first correction patterns; determining a correction pattern to be processed from the plurality of first correction patterns based on each of the first edge placement errors; obtaining a target pattern to be compensated corresponding to the correction pattern to be processed from the plurality of first target patterns; compensating the target pattern to be compensated based on the first edge placement errors to obtain a second target pattern; and performing a second optical proximity correction on the correction pattern to be processed based on the second target pattern to obtain a second correction pattern. The method provides accurate correction results.

Description

Technical Field

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

[0002] With the advancement of semiconductor technology and the reduction in critical dimensions of semiconductor structures, the optical proximity effect (OPC) in the lithography process has become increasingly difficult to ignore and even impacts the process flow. Optical Proximity Correction (OPC) technology has become necessary to ensure that the exposed pattern meets the process requirements at each node. OPC minimizes the edge placement error (EPE) between the final simulated pattern and the target pattern by continuously modifying key pattern boundaries.

[0003] However, for high-density nodes, in certain special circumstances, due to constraints between graphics layers or non-convergence of the optical proximity correction process, it is often difficult to simultaneously optimize edge placement errors across all edges during the correction process. For edges with more stringent constraints, achieving the required edge placement error is even more difficult, necessitating the use of more flexible optical proximity correction methods. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a graphics correction method to improve the accuracy of graphics correction results.

[0005] To solve the above technical problems, the technical solution of the present invention provides a graphic correction method, comprising: providing a layout to be corrected, the layout to be corrected including several graphics to be corrected; providing a first target layout, the first target layout including several first target graphics, the first target graphics corresponding one-to-one to the several graphics to be corrected; performing a first optical proximity correction on the layout to be corrected to obtain a first correction layout, the first correction layout including several first correction graphics corresponding to the graphics to be corrected; obtaining a first edge placement error of the several first correction graphics; determining a correction graphic to be processed from several first correction graphics based on each of the first edge placement errors; obtaining a target graphic to be compensated corresponding to the correction graphic to be processed from the several first target graphics; compensating the target graphic to be compensated according to the first edge placement error to obtain a second target graphic; performing a second optical proximity correction on the correction graphic to be processed according to the second target graphic to obtain a second correction graphic.

[0006] Optionally, the method for obtaining first edge placement errors of several first correction graphics includes: dividing the contour of the first correction graphics into several line segments; performing simulated exposure on the first correction layout to obtain a first simulated exposure layout, the first simulated exposure layout including several first simulated exposure graphics corresponding to the first correction graphics; obtaining several first edge placement errors between several line segments of the contours of the several first simulated exposure graphics and the contours of the corresponding first target graphics.

[0007] Optionally, obtaining a number of first edge placement errors between a number of line segments of a number of first simulated exposure graphic contours and the contours of a corresponding first target graphic includes: calculating the offset between the line segments of the first simulated exposure graphic contours and the corresponding line segments of the first target graphic contours, obtaining the first edge placement errors, and the number of first edge placement errors corresponding to the line segments.

[0008] Optionally, determining a correction graphic to be processed among several first correction graphics based on each of the first edge placement errors includes: when the first edge placement error does not meet a preset condition, determining the first correction graphic as a correction graphic to be processed.

[0009] Optionally, the preset condition includes: the first edge placement error is 0.

[0010] Optionally, compensating the target graphic to be compensated based on the first edge placement error includes: if the first edge placement error is greater than 0, shrinking the contour line segment corresponding to the target graphic to be compensated, and the shrinkage value is the absolute value of the first edge placement error; if the first edge placement error is less than 0, expanding the contour line segment corresponding to the target graphic to be compensated, and the expansion value is the absolute value of the first edge placement error.

[0011] Optionally, performing a first optical proximity correction on the to-be-corrected layout to obtain a first corrected layout includes: dividing the contour of the to-be-corrected pattern into a plurality of line segments; performing simulated exposure on the to-be-corrected layout to obtain a second simulated exposure layout, wherein the second simulated exposure layout includes a plurality of second simulated exposure patterns corresponding to the to-be-corrected pattern; obtaining a second edge placement error between the plurality of line segments of the second simulated exposure pattern and the contour line segments of the first target pattern; correcting the contour of the to-be-corrected pattern according to the second edge placement error, and obtaining a first corrected layout after a plurality of corrections.

[0012] Optionally, after obtaining the second corrected pattern, the method further includes: performing simulated exposure on the second corrected pattern to obtain a third simulated exposure layout, wherein the third simulated exposure layout includes several third simulated exposure patterns corresponding to the second corrected pattern, and the edge placement error between the outline of the third simulated exposure pattern and the outline of the first target pattern meets a preset condition.

[0013] Optionally, the first optical proximity correction rule includes a mask restriction rule.

[0014] Optionally, compensating the target graphic to be compensated according to the first edge placement error includes: compensating the target graphic to be compensated according to the first edge placement error corresponding to the corrected graphic to be processed.

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

[0016] The technical solution of the present invention obtains the first edge placement errors of several first correction patterns, compensates the target patterns to be compensated corresponding to the correction patterns to be processed whose first edge placement errors do not meet the preset conditions, redefines the target layout, and then performs a second optical proximity correction on the correction patterns to be processed whose first edge placement errors do not meet the preset conditions based on the compensated second target pattern. By adjusting the target pattern, the correction result after this second optical proximity correction can be close to the initial first target pattern, achieving the desired correction result. This makes the correction process more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of an optical correction process in one embodiment;

[0018] Figures 2 to 5 4 is a flow chart of a graphics correction method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] As described in the background art, a more flexible optical proximity effect correction method is needed, which will now be analyzed and explained in conjunction with specific embodiments.

[0020] Figure 1 Schematic diagram of an optical correction process in one embodiment.

[0021] Please refer to Figure 1 , providing a layout to be corrected 100, wherein the layout to be corrected 100 includes a plurality of graphics to be corrected 103; providing a target layout, wherein the target layout includes a plurality of target graphics 102; performing optical proximity correction on the layout to be corrected 100 to obtain a corrected layout, wherein the corrected layout includes a plurality of corrected graphics 104.

[0022] In this embodiment, the to-be-corrected layout 100 is located on a lower layout, and the lower layout includes a plurality of lower patterns 101 . Some of the to-be-corrected patterns 103 have lower patterns 101 on both sides in the first direction X.

[0023] During the correction process, due to mask restrictions, the spacing between the corrected pattern 104 and the underlying patterns 101 on either side must be greater than the minimum spacing to prevent short circuits between the upper and lower layers. Consequently, after multiple corrections, the edge placement error of the corrected pattern cannot approach zero, resulting in non-convergence of the correction results. This causes the corrected pattern 104 to increase in size in the second direction Y, and the edge placement error of the corrected pattern 104 in the second direction X to fail to meet the requirements, resulting in a poor correction result.

[0024] To address the aforementioned issues, the present invention provides a pattern correction method. This method obtains the first edge placement errors of several first correction patterns, compensates target patterns corresponding to those to-be-corrected patterns whose first edge placement errors do not meet preset conditions, redefines the target layout, and then performs a second optical proximity correction on those to-be-corrected patterns whose first edge placement errors do not meet preset conditions based on the compensated second target pattern. By adjusting the target pattern, the correction result after this second optical proximity correction can be brought close to the initial first target pattern, thereby achieving a satisfactory correction result. This makes the correction process more precise.

[0025] 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.

[0026] Figures 2 to 5 4 is a flow chart of a graphics correction method according to an embodiment of the present invention.

[0027] Please refer to Figure 2 , the graphics correction method includes:

[0028] Step S10: providing a layout to be corrected, wherein the layout to be corrected includes a plurality of graphics to be corrected;

[0029] Step S20: providing a first target layout, wherein the first target layout includes a plurality of first target patterns, and the first target patterns correspond one-to-one to a plurality of patterns to be corrected;

[0030] Step S30: performing a first optical proximity correction on the to-be-corrected layout to obtain a first corrected layout, wherein the first corrected layout includes a plurality of first corrected patterns corresponding to the to-be-corrected patterns;

[0031] Step S40: obtaining first edge placement errors of a plurality of first correction patterns;

[0032] Step S50: determining a correction pattern to be processed among a plurality of first correction patterns based on each of the first edge placement errors;

[0033] Step S60: obtaining a target pattern to be compensated corresponding to the pattern to be corrected from the plurality of first target patterns;

[0034] Step S70: compensating the target pattern to be compensated according to the first edge placement error to obtain a second target pattern;

[0035] Step S80: performing a second optical proximity correction on the to-be-processed correction pattern according to the second target pattern to obtain a second correction pattern.

[0036] This correction method obtains the first edge placement errors of several first correction patterns, compensates target patterns corresponding to those correction patterns whose first edge placement errors do not meet preset conditions, redefines the target layout, and then performs a second optical proximity correction on those correction patterns whose first edge placement errors do not meet preset conditions based on the compensated second target pattern. By adjusting the target pattern, the correction result after this second optical proximity correction can be close to the initial first target pattern, achieving a satisfactory correction result. This makes the correction process more accurate.

[0037] Next, each step will be described separately.

[0038] Please continue to refer to Figure 2 , executing step S10: providing a layout to be corrected, wherein the layout to be corrected includes a plurality of graphics to be corrected.

[0039] The layout to be corrected is a mask layout that requires optical proximity correction.

[0040] Please continue to refer to Figure 2 , executing step S20: providing a first target layout, wherein the first target layout includes a plurality of first target graphics, and the first target graphics correspond one-to-one to a plurality of graphics to be corrected.

[0041] The first target layout is a layout formed after the layout to be corrected needs to be corrected.

[0042] Please continue to refer to Figure 2 , executing step S30: performing a first optical proximity correction on the to-be-corrected layout to obtain a first corrected layout, wherein the first corrected layout includes a plurality of first corrected patterns corresponding to the to-be-corrected patterns.

[0043] The first corrected layout is a layout in which the edge placement error is preliminarily converged after performing several optical proximity corrections on the layout to be corrected.

[0044] Please refer to Figure 3 In this embodiment, a method for performing a first optical proximity correction on the layout to be corrected to obtain a first corrected layout includes:

[0045] Step S301: dividing the outline of the graphic to be corrected into a number of line segments;

[0046] Step S302: performing simulated exposure on the to-be-corrected layout to obtain a second simulated exposure layout, wherein the second simulated exposure layout includes a plurality of second simulated exposure patterns corresponding to the to-be-corrected patterns;

[0047] Step S303: obtaining second edge placement errors between the plurality of line segments of the second simulated exposure pattern and the contour line segments of the first target pattern;

[0048] Step S304: Correcting the outline of the pattern to be corrected according to the second edge placement error, and obtaining a first corrected layout after several corrections.

[0049] The first optical proximity correction rule includes a mask restriction rule, which is a rule of minimum spacing that must be satisfied by adjacent patterns.

[0050] The obtaining of second edge placement errors between the plurality of line segments of the second simulated exposure pattern and the line segments of the first target pattern contour includes: calculating the offset between the line segments of the second simulated exposure pattern contour and the corresponding line segments of the first target pattern contour, obtaining the second edge placement errors, and the plurality of line segments corresponding to the plurality of second edge placement errors.

[0051] Please continue to refer to Figure 2 , executing step S40: obtaining first edge placement errors of a plurality of first correction patterns.

[0052] Please refer to Figure 4 In this embodiment, the method for obtaining first edge placement errors of a plurality of first correction patterns includes:

[0053] Step S401: dividing the outline of the first corrected figure into a plurality of line segments;

[0054] Step S402: performing simulated exposure on the first revised layout to obtain a first simulated exposure layout, wherein the first simulated exposure layout includes a plurality of first simulated exposure patterns corresponding to the first revised patterns;

[0055] Step S403: obtaining a plurality of first edge placement errors between a plurality of line segments of a plurality of first simulated exposure pattern contours and a corresponding contour of a first target pattern.

[0056] The step of obtaining a plurality of first edge placement errors between a plurality of line segments of a plurality of first simulated exposure pattern contours and a corresponding first target pattern contour includes calculating an offset between a line segment of the first simulated exposure pattern contour and a corresponding line segment of the first target pattern contour, obtaining the first edge placement error, and the plurality of line segments corresponding to the plurality of first edge placement errors.

[0057] Please continue to refer to Figure 2 , executing step S50: determining a correction pattern to be processed among a plurality of first correction patterns based on each of the first edge placement errors.

[0058] In this embodiment, when the first edge placement error does not meet a preset condition, the first correction pattern is determined to be a correction pattern to be processed.

[0059] In this embodiment, the preset condition includes: the first edge placement error is 0. That is, in the first correction pattern, when the first edge placement error of the first correction pattern is greater than 0 or less than 0, the first correction pattern is the correction pattern to be processed.

[0060] In other embodiments, the preset condition may be other conditions.

[0061] Please continue to refer to Figure 2 , executing step S60: obtaining a target pattern to be compensated corresponding to the pattern to be corrected from the plurality of first target patterns.

[0062] The first target pattern corresponds to the first correction pattern one by one, thereby obtaining a target pattern to be compensated corresponding to the correction pattern to be processed.

[0063] Please continue to refer to Figure 2 , executing step S70: compensating the target pattern to be compensated according to the first edge placement error to obtain a second target pattern.

[0064] Please refer to Figure 5 In this embodiment, the method for compensating the target pattern to be compensated according to the first edge placement error includes:

[0065] Step S701: if the first edge placement error is greater than 0, the contour line segment corresponding to the target figure to be compensated is retracted, and the retraction value is the absolute value of the first edge placement error;

[0066] Step S702: If the first edge placement error is less than 0, the contour line segment corresponding to the target graphic to be compensated is expanded, and the expansion value is the absolute value of the first edge placement error.

[0067] By compensating the target pattern to be compensated for the first correction pattern whose edge placement error does not meet the preset conditions, the target layout is redefined, and then a second optical proximity correction is performed on the correction pattern whose first edge placement error does not meet the preset conditions based on the compensated second target pattern. By adjusting the target pattern, the correction result after the second optical proximity correction can be close to the initial first target pattern, achieving the desired correction result, making the correction process more accurate.

[0068] Please continue to refer to Figure 2 , executing step S80: performing a second optical proximity correction on the to-be-processed correction pattern according to the second target pattern to obtain a second correction pattern.

[0069] A second optical proximity correction is performed on the to-be-processed correction pattern according to the adjusted second target pattern. The correction result after the second optical proximity correction can be close to the initial first target pattern, so as to achieve the purpose of satisfying the correction result.

[0070] In this embodiment, after obtaining the second correction pattern, the method further includes: performing simulated exposure on the second correction pattern to obtain a third simulated exposure layout, wherein the third simulated exposure layout includes a plurality of third simulated exposure patterns corresponding to the second correction pattern.

[0071] The edge placement error between the outline of the third simulated exposure pattern and the outline of the first target pattern satisfies a preset condition, thereby achieving the purpose of satisfying the correction result and making the correction process more accurate.

[0072] 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 graphics correction method, characterized in that: include: Providing a layout to be revised, wherein the layout to be revised includes a plurality of graphics to be revised; Providing a first target layout, wherein the first target layout includes a plurality of first target graphics, and the first target graphics correspond one-to-one to a plurality of graphics to be corrected; Performing a first optical proximity correction on the to-be-corrected layout to obtain a first corrected layout, wherein the first corrected layout includes a plurality of first corrected patterns corresponding to the to-be-corrected patterns; Obtaining first edge placement errors of a plurality of first correction figures; determining a correction pattern to be processed among a plurality of first correction patterns based on each of the first edge placement errors; Acquire a target pattern to be compensated corresponding to the pattern to be corrected from among the plurality of first target patterns; Compensating the target pattern to be compensated according to the first edge placement error to obtain a second target pattern; A second optical proximity correction is performed on the to-be-processed correction pattern according to the second target pattern to obtain a second correction pattern.

2. The image correction method according to claim 1, wherein: The method for obtaining first edge placement errors of a plurality of first correction patterns includes: dividing the outline of the first corrected figure into a plurality of line segments; Performing simulated exposure on the first revised layout to obtain a first simulated exposure layout, wherein the first simulated exposure layout includes a plurality of first simulated exposure patterns corresponding to the first revised patterns; A plurality of first edge placement errors between a plurality of line segments of a plurality of first simulated exposure pattern contours and a corresponding contour of a first target pattern are obtained.

3. The image correction method according to claim 2, wherein: The step of obtaining a plurality of first edge placement errors between a plurality of line segments of a plurality of first simulated exposure pattern contours and a corresponding first target pattern contour includes calculating an offset between a line segment of the first simulated exposure pattern contour and a corresponding line segment of the first target pattern contour, obtaining the first edge placement error, and the plurality of line segments corresponding to the plurality of first edge placement errors.

4. The image correction method according to claim 1, wherein: The step of determining a correction pattern to be processed from among the plurality of first correction patterns based on each of the first edge placement errors includes: When the first edge placement error does not meet a preset condition, the first correction pattern is determined to be a correction pattern to be processed.

5. The image correction method according to claim 4, wherein: The preset condition includes: the first edge placement error is 0.

6. The image correction method according to claim 5, wherein: The compensating the target graphic to be compensated according to the first edge placement error includes: If the first edge placement error is greater than 0, the contour line segment corresponding to the target figure to be compensated is retracted, and the retraction value is the absolute value of the first edge placement error; If the first edge placement error is less than 0, the contour line segment corresponding to the target graphic to be compensated is expanded, and the expansion value is the absolute value of the first edge placement error.

7. The image correction method according to claim 1, wherein: The step of performing a first optical proximity correction on the layout to be corrected to obtain a first corrected layout includes: Cutting the outline of the figure to be corrected into a plurality of line segments; Performing simulated exposure on the to-be-corrected layout to obtain a second simulated exposure layout, wherein the second simulated exposure layout includes a plurality of second simulated exposure patterns corresponding to the to-be-corrected patterns; obtaining second edge placement errors between the plurality of line segments of the second simulated exposure pattern and the contour line segments of the first target pattern; The contour of the pattern to be corrected is corrected according to the second edge placement error, and a first corrected layout is obtained after several corrections.

8. The image correction method according to claim 1, wherein: After obtaining the second correction pattern, the method further includes: performing simulated exposure on the second correction pattern to obtain a third simulated exposure layout, wherein the third simulated exposure layout includes a plurality of third simulated exposure patterns corresponding to the second correction pattern, and an edge placement error between an outline of the third simulated exposure pattern and an outline of the first target pattern meets a preset condition.

9. The image correction method according to claim 1, wherein: The first optical proximity correction rule includes a mask restriction rule.

10. The image correction method according to claim 1, wherein: The compensating the target pattern to be compensated according to the first edge placement error includes: compensating the target pattern to be compensated according to the first edge placement error corresponding to the corrected pattern to be processed.

Images