Optical proximity correction method

Abstract

An optical proximity correction method includes: obtaining a key region in a first layout, the first layout including a plurality of first patterns, the first patterns partially located in the key region; performing contour cutting on the plurality of first patterns to form a plurality of first segments, the contour cutting being performed based on a plurality of intersection points between a contour of each first pattern and a boundary of the key region, the intersection points being cutting origins; and performing offset processing on the plurality of first segments to form a second layout. The optical proximity correction method can improve the efficiency and accuracy of optical proximity correction.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more particularly to an optical proximity correction method. Background Technology

[0002] Photolithography is a crucial technology in semiconductor manufacturing. It transfers patterns from a photomask to the surface of a silicon wafer, forming semiconductor products that meet design requirements. The photolithography process includes an exposure step, a development step following exposure, and an etching step following development. In the exposure step, light passes through the light-transmitting areas of the photomask and shines onto the silicon wafer coated with photoresist, causing a chemical reaction in the photoresist. In the development step, the different solubility of the developer in the photoresist and the non-photoresist is used to form a photolithographic pattern, transferring the photomask pattern onto the photoresist. In the etching step, the silicon wafer is etched based on the photolithographic pattern formed by the photoresist layer, further transferring the photomask pattern onto the silicon wafer.

[0003] In semiconductor manufacturing, as design dimensions continue to shrink and approach the limits of photolithography imaging systems, the diffraction effect of light becomes increasingly pronounced, leading to optical image degradation of the final design pattern. The actual photolithographic pattern formed is severely distorted relative to the pattern on the mask, resulting in a difference between the actual pattern formed on the silicon wafer and the design pattern. This phenomenon is called the Optical Proximity Effect (OPE).

[0004] To correct the optical proximity effect, Optical Proximity Correction (OPC) was developed. The core idea of ​​OPC is to establish an OPC model based on the consideration of counteracting the optical proximity effect. The photomask pattern is designed according to the OPC model. In this way, although the lithographic pattern and the corresponding photomask pattern have an optical proximity effect, the cancellation of this phenomenon has been considered when designing the photomask pattern according to the OPC model. Therefore, the lithographic pattern after photolithography is close to the target pattern actually desired by the user.

[0005] However, existing optical proximity correction technologies still have many problems. Summary of the Invention

[0006] The technical problem solved by this invention is to provide an optical proximity correction method to improve the efficiency and accuracy of correction.

[0007] To solve the above-mentioned technical problems, the present invention provides an optical proximity correction method, comprising: obtaining a key region in a first layout, the first layout comprising a plurality of first graphics, the first graphics being partially located within the key region; using a plurality of intersection points between the contour of each first graphic and the boundary of the key region as cutting origins, contour cutting is performed on the plurality of first graphics to form a plurality of first segments; and offset processing is performed on the plurality of first segments to form a second layout.

[0008] Optionally, the method further includes: performing exposure processing on the first image to obtain a first exposed image; obtaining edge placement error data of the first exposed image; and performing offset processing on a plurality of first segments, which further includes: performing offset processing on a plurality of first segments based on the edge placement error data of the first exposed image.

[0009] Optionally, the first exposure layout includes a plurality of first exposure patterns corresponding to a plurality of first patterns, and a key exposure area corresponding to the key area, and the edge placement error data of the first exposure layout includes edge placement error parameters of each first exposure pattern; the method for obtaining the edge placement error parameters of each first exposure pattern includes: obtaining the inner edge placement error parameter of any first exposure pattern within the key exposure area; obtaining the outer edge placement error parameter of the any first exposure pattern outside the key exposure area; and obtaining the edge placement error parameter of the any first exposure pattern based on the inner edge placement error parameter and the outer edge placement error parameter.

[0010] Optionally, it further includes: obtaining a first weighting coefficient corresponding to the inner edge placement error parameter and a second weighting coefficient corresponding to the outer edge placement error parameter; the step of obtaining the edge placement error parameter of the arbitrary first exposure pattern based on the inner edge placement error parameter and the outer edge placement error parameter of the arbitrary first exposure pattern includes: determining the edge placement error parameter of the arbitrary first exposure pattern based on the inner edge placement error parameter, the outer edge placement error parameter, the first weighting coefficient, and the second weighting coefficient.

[0011] Optionally, the ratio of the first weighting coefficient to the second weighting coefficient is in the range of 1.5 to 4.0.

[0012] Optionally, the plurality of first segments include a plurality of first inner segments located within a critical region, and the outline of the plurality of first exposure patterns includes a plurality of first inner exposure segments located within the critical exposure region and corresponding to the plurality of first inner segments; the method for obtaining the inner edge placement error parameter of any first exposure pattern includes: obtaining the edge placement error of each first inner exposure segment of the arbitrary first exposure pattern; determining the sum of squares of the edge placement errors of all first inner exposure segments of the arbitrary first exposure pattern to obtain the inner edge placement error parameter of the arbitrary first exposure pattern.

[0013] Optionally, the plurality of first segments further includes a plurality of first outer segments located outside the critical area, and the outline of the plurality of first exposure patterns further includes a plurality of first outer exposure segments located outside the critical exposure area and corresponding to the plurality of first outer segments; the method for obtaining the outer edge placement error parameter of any first exposure pattern includes: obtaining the edge placement error of each first outer exposure segment of the arbitrary first exposure pattern; determining the sum of squares of the edge placement errors of all first outer exposure segments of the arbitrary first exposure pattern to obtain the outer edge placement error parameter of the arbitrary first exposure pattern.

[0014] Optionally, the method of offsetting several first segments based on the edge placement error data of the first exposure pattern to form a second pattern includes: when the edge placement error parameter of any first exposure pattern exceeds the preset edge placement error parameter range, offsetting several first segments corresponding to the arbitrary first exposure pattern based on the edge placement error parameter of the arbitrary first exposure pattern.

[0015] Optionally, the method of offsetting several first segments based on the edge placement error data of the first exposure pattern to form a second pattern further includes: when the edge placement error parameters of each first exposure pattern are all within the range of preset edge placement error parameters, then the first pattern is used as the second pattern.

[0016] Optionally, the plurality of first segments include a plurality of first inner segments located within the critical region and a plurality of first outer segments located outside the critical region, wherein the length of any first inner segment is less than the length of any first outer segment.

[0017] Optionally, the method for obtaining the key area in the first layout includes: providing a layout of the preceding graphics, the layout of the preceding graphics including the preceding key graphics; and determining the key area in the first layout based on the key preceding graphics.

[0018] Optionally, the method for obtaining the first layout includes: providing a target layout, the target layout including a plurality of target graphics; performing an exposure process on the target layout to obtain a plurality of exposed graphics; performing an etching process using the plurality of exposed graphics as a mask to obtain a plurality of etched graphics; performing post-etching detection on the plurality of etched graphics based on the plurality of target graphics to obtain etching deviation data; and performing edge-shifting compensation processing on the contours of the plurality of target graphics based on the etching deviation data to form the first layout.

[0019] Optionally, the target map includes a first area and a second area arranged along a first direction, the target graphic extends in a second direction, the first direction and the second direction are perpendicular to each other, a plurality of target graphics are located in the first area, a plurality of target graphics are located in the second area, and, in the first direction, the spacing between adjacent target graphics in the first area is less than the spacing between any target graphic in the second area and the boundary of the second area.

[0020] Optionally, the method for compensating and shifting the contours of several target graphics includes: shifting the edges of the contours of several target graphics parallel to the first direction in a second direction to increase the length of the target graphics in the second direction, and wherein the shift distance of the edges of the target graphics in the second region is greater than the shift distance of the edges of the target graphics in the first region.

[0021] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0022] In the optical proximity correction method provided by the present invention, since a key region is obtained in the first pattern, and several intersection points of the contour of each first graphic with the boundary of the key region are used as cutting origins, several first graphics are contour-cut to form several first segments. Therefore, when contour-cutting inside and outside the key region, the correlation between the lengths of the first segments inside and outside the key region is small. Thus, not only is the length of the first segments inside and outside the key region well controllable, but the length of the first segments near the boundary of the key region is also easy to reach the expected length. Furthermore, the rules for contour cutting are simpler. In addition, when offsetting several first segments, the accuracy of edge selection can be improved. As a result, the contour convergence effect of the exposed graphic formed after the second pattern is exposed is good, and it can get closer to or achieve the convergence target, thereby improving the efficiency and accuracy of optical proximity correction. Attached Figure Description

[0023] Figure 1 and Figure 2 This is a schematic diagram of the steps in a layout correction method.

[0024] Figure 3 This is a schematic diagram of contour cutting in an optical proximity correction process;

[0025] Figure 4 This is a schematic flowchart of an optical proximity correction method according to an embodiment of the present invention;

[0026] Figures 5 to 10 This is a schematic diagram of the structure of each step of an optical proximity correction method according to an embodiment of the present invention. Detailed Implementation

[0027] As described in the background section, existing optical proximity correction techniques still have many problems. These will be explained in detail below.

[0028] Figure 1 and Figure 2 This is a schematic diagram illustrating the steps involved in a layout correction method. Figure 3 This is a schematic diagram of contour cutting in an optical proximity correction process.

[0029] Please refer to Figure 1 The system provides a target layout 100, which includes several target patterns 101 in a key region A; exposes the several target patterns 101 to form several exposed patterns (not shown); performs etching using the several exposed patterns as masks to obtain etched patterns (not shown); and detects the etching deviation between the etched patterns and the several target patterns 101.

[0030] Please refer to Figure 2 Based on the etching deviation, etching deviation compensation is performed on several target patterns 101, and several target patterns 101 are grown in the extension direction Z of the target patterns 101 to form a first layout 110 including several first patterns 111.

[0031] Next, several optical proximity correction steps are performed on the first pattern 110 to form a corrected pattern.

[0032] Please refer to Figure 3 In the optical proximity correction, the first graphic 111 is contour-cut using the contour vertex of the first graphic 111 as the cutting origin 112 to form a number of fragments 113, and the edges of the fragments 113 are then moved.

[0033] However, on the one hand, several target graphics 101 are in region B (such as...) Figure 1 (as shown) and region C (as shown) Figure 1 The arrangement density of the target patterns 101 in region B is different, while the spacing between them is small, and the spacing between them is large. Correspondingly, etching load deviations will occur during the etching process. Therefore, the amount of deviation compensation applied to the target patterns 101 in regions B and C is different, resulting in a difference in the spacing D between the outlines of several first patterns 111 and the boundary of the critical region A (as shown). Figure 2(As shown) is different. On the other hand, when contour cutting is performed using the contour vertices of each first graphic 111 as the cutting origin 112, the cutting origin 112 is a certain distance from the boundary of the key region A, resulting in lower controllability of the length of the segment 113 formed at the boundary of the key region A. Therefore, it is difficult to simultaneously consider the contour cutting of each first graphic 111, which not only easily results in segments 113 crossing the boundary of the key region A, but also in the fact that the length of the segment 113 formed at the boundary of the key region A differs greatly from the expected length, thus causing poor accuracy of optical proximity correction. Moreover, in order to minimize the number of segments 113 crossing the boundary of the key region A and form segments 113 closer to the expected length, it is necessary not only to adjust the contour cutting rules multiple times, but also to set complex contour cutting rules, thus the efficiency of optical proximity correction is also poor.

[0034] To solve the above-mentioned technical problems, the technical solution of the present invention provides an optical proximity correction method. By obtaining a key area in a first layout and using several intersection points between the contour of each first graphic and the boundary of the key area as cutting origins, the contours of several first graphics are cut, which can effectively improve the correction efficiency and accuracy of optical proximity correction.

[0035] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Figure 4 This is a schematic flowchart of an optical proximity correction method according to an embodiment of the present invention.

[0037] Please refer to Figure 4 Optical proximity correction methods include:

[0038] Step S100: Obtain a first layout, the first layout including a plurality of first graphics;

[0039] Step S200: Obtain the key area in the first layout, wherein the first graphic portion is located within the key area;

[0040] Step S300: Using several intersection points between the outline of each first graphic and the boundary of the key area as the cutting origin, the outlines of several first graphics are cut to form several first segments.

[0041] Step S400: Perform exposure processing on the first map to obtain the first exposed map;

[0042] Step S500: Obtain the edge placement error data of the first exposure pattern;

[0043] Step S600: Offset several first segments to form a second layout.

[0044] It should be noted that optical proximity correction methods typically include several iterative correction processes. Steps S100 to S600 in this embodiment are steps within one iterative correction. Based on this, the first layout is the layout to be corrected in the current iterative correction, and the second layout is the corrected layout in the current iterative correction. Furthermore, in the case of the next iterative correction, the second layout will also be the layout to be corrected in that next iterative correction.

[0045] The following is a detailed description in conjunction with the accompanying drawings.

[0046] Figures 5 to 10 This is a schematic diagram of the structure of each step of an optical proximity correction method according to an embodiment of the present invention.

[0047] First, obtain the first map, which includes several first graphics.

[0048] In this embodiment, the first layout of the nth iteration is obtained based on the (n-1)th historical iteration, where n is a natural number greater than 1. For the specific steps of obtaining the first layout of the initial iteration, please refer to [link to documentation]. Figure 5 and Figure 6 .

[0049] Please refer to Figure 5 A target layout 200 is provided, which includes a plurality of target graphics 210.

[0050] The target pattern 210 is an ideal pattern (i.e., without optical proximity effect). However, due to the existence of optical proximity effect, light interference and diffraction occur during the actual exposure process. Therefore, there is a difference between the pattern obtained after exposure and the target pattern 210. For example, the target pattern 210 is a regular rectangle, while the pattern obtained after exposure is similar to an ellipse.

[0051] By modifying the target layout 200, a layout for transferring the current layer pattern is formed, which is used to form a fin, remove the entire fin, or cut off the fin.

[0052] In this embodiment, the target layout 200 includes a first region I and a second region II arranged along the first direction X, and the target pattern 210 extends along the second direction Y.

[0053] In this context, the first direction X and the second direction Y are perpendicular to each other.

[0054] In this embodiment, several target graphics 210 are located in a first region I and several target graphics 210 are located in a second region II. Furthermore, in the first direction X, the distance between adjacent target graphics 210 in the first region I is less than the distance D2 between any target graphics 210 in the second region II and the boundary of the second region II.

[0055] It should be noted that, for ease of explanation, Figure 5 The diagram schematically shows one target graphic 210 in the second zone II.

[0056] Specifically, in this embodiment, the first region I is a dense region, and the second region II is an isoregion.

[0057] When there are more than two target graphics 210 in the second zone II, the spacing between adjacent target graphics 210 in the first zone I is smaller than the spacing between adjacent target graphics 210 in the second zone II.

[0058] In this embodiment, after providing the target layout 200, the target layout 200 is exposed to obtain several exposed patterns (not shown); the several exposed patterns are used as masks to perform etching to obtain several etched patterns (not shown); based on the several target patterns 210, the several etched patterns are subjected to after-etching inspection (AEI) to obtain etching deviation data.

[0059] In other embodiments, etching deviation data is obtained by querying empirical data based on the feature dimensions of several target patterns 210.

[0060] The feature dimensions include: the length and width of the graphic, and the spacing between it and adjacent graphics.

[0061] Please refer to Figure 6 Based on the etching deviation data, the contours of several target patterns 210 are compensated and edge-shifted to form a first layout 300, which includes several first patterns 310 corresponding to several target patterns 210.

[0062] In this embodiment, the method for compensating and shifting the contours of several target graphics 210 includes: shifting the edges 211 parallel to the first direction X in the contours of several target graphics 210 in the second direction Y to increase the length of the target graphics 210 in the second direction X, and wherein, in the shift, the shift distance L2 of the edge 211 of the target graphics 210 in the second region II is greater than the shift distance L1 of the edge 211 of the target graphics 210 in the first region I.

[0063] It should be noted that, for ease of understanding, Figure 6 The edge 211 of the target graphic 210 is schematically represented by a dashed line.

[0064] In this embodiment, the reason for making the offset distance L2 greater than the offset distance L1 is that: the first region I is a dense region and the second region II is a sparse region. Compared with the first region I, the target pattern 210 in the second region II has a larger spacing with the surrounding patterns. Therefore, compared with the first region I, when transferring the pattern of the target pattern 210 in the second region II to the current layer of the wafer, the etching process has a faster etching speed on the material, and the difference between the etched pattern and the expected pattern is larger. Thus, by compensating the target pattern 210 in the second region II with a larger offset distance L2, the difference between the etched pattern and the expected pattern can be reduced more accurately.

[0065] Next, steps S200 to S600 will be described with reference to the following accompanying drawings. It should be noted that, for ease of explanation and understanding, Figures 7 to 10 Taking the initial iteration correction process as an example (i.e., based on the first version 300), steps S200 to S600 in this embodiment will be explained.

[0066] Please refer to Figure 7 In the first layout 300, a key area K is obtained, and part of the first graphic 310 is located within the key area K.

[0067] In this embodiment, the method for obtaining the key region K in the first layout 300 includes: providing a layout of a preceding graphic (not shown), the layout of the preceding graphic including a preceding key graphic (not shown); and determining the key region K in the first layout 300 based on the key preceding graphic.

[0068] Specifically, the key area K can be divided in the first layout 300 by comparing the layout of the previous layer graphic with the first layout 300.

[0069] In this embodiment, the key front-layer pattern is used to transfer the pattern to the wafer to form an active region.

[0070] In this embodiment, the length of the key region K in the second direction Y is the same as the length of the target graphic 210 in the second direction Y. Specifically, when comparing the first layout 300 with the target layout 200, several target graphics 210 are located within the key region K, and the edges 211 of the target graphics 210 coincide with the boundary of the key region K.

[0071] Please refer to Figure 8 Using the intersection points of the outline of each first graphic 310 and the boundary of the key area K as the cutting origin 311, the outlines of the first graphics 310 are cut to form a number of first segments 312.

[0072] In this embodiment, the plurality of first segments 312 include: a plurality of first inner segments 312a located within the critical region K, and a plurality of first outer segments 312b located outside the critical region K.

[0073] Preferably, the length of any first inner segment 312a is less than the length of any first outer segment 312b, so that the first segment 312 within the key region K can be offset more finely and with higher precision in the subsequent process, thereby improving the accuracy of optical proximity correction.

[0074] Please refer to Figure 9 The first layout 300 is exposed to obtain the first exposed layout 400.

[0075] The first exposure pattern 400 includes: a plurality of first exposure patterns 410 corresponding to a plurality of first patterns 310, and a key exposure area SK corresponding to the key area K.

[0076] In this embodiment, the exposure processing is a simulation processing of simulated exposure.

[0077] Please continue to refer to this. Figure 9 Obtain edge placement error data for the first exposure layout 400.

[0078] In this embodiment, the edge placement error data of the first exposure pattern 400 includes: the edge placement error parameter (MSE) of each first exposure pattern 410.

[0079] In this embodiment, the method for obtaining the edge placement error parameter MSE of each first exposure pattern 410 includes: obtaining the inner edge placement error parameter E of any first exposure pattern 410 within the critical exposure area SK. in ; Obtain the error parameter E for placing the arbitrary first exposure pattern 410 at the outer edge outside the critical exposure area SK. out According to the placement error parameter E of the inner edge of the arbitrary first exposure pattern 410 in and the outer edge placement error parameter E out Obtain the edge placement error parameter MSE of the arbitrary first exposure pattern 410.

[0080] In this embodiment, the optical proximity correction method further includes: obtaining a first weighting coefficient W corresponding to the inner edge placement error parameter. in And the second weighting coefficient W corresponding to the outer edge placement error parameter. out .

[0081] The placement error parameter E based on the inner edge of the arbitrary first exposure pattern 410 in and the outer edge placement error parameter Eout Obtaining the edge placement error parameter MSE of the arbitrary first exposure pattern 410 includes: based on the inner edge placement error parameter E in Outer edge placement error parameter E out First weighting coefficient W in and the second weighting coefficient W out The edge placement error parameter MSE of the arbitrary first exposure pattern 410 is determined.

[0082] Specifically, the MSE = W in ×E in +W out ×E out .

[0083] Wherein, the W in Greater than W out .

[0084] In this embodiment, by comparing the contours of several first patterns 310 of the first layout 300 (i.e., the first layout 300 formed by compensating and shifting the contours of several target patterns 210 according to the etching deviation data) with the contours of several first exposed patterns 410 of the first exposed layout 400, several inner edge placement error parameters E are obtained. in and several of the outer edge placement error parameters E out .

[0085] Since the edge placement error data of the first exposure pattern 400 includes the edge placement error parameter MSE of each first exposure pattern 410, and based on the inner edge placement error parameter E of any first exposure pattern 410... in and the outer edge placement error parameter E out Obtain the edge placement error parameter MSE = W of the arbitrary first exposure pattern 410. in ×E in +W out ×E out And the W in Greater than W out Therefore, in the edge placement error data, the weight of the edge placement error of the first exposure pattern 410 contour within the critical exposure area SK is increased, thereby increasing the contour convergence priority in the critical exposure area SK, and thus improving the efficiency and accuracy of optical proximity correction.

[0086] In this embodiment, the W in With W out The proportion W in / W out The range is 1.0 to 9.0.

[0087] Preferably, the first weighting coefficient W in With the second weighting coefficient W out The proportion (W) in / W out The range is 1.5 to 4.0.

[0088] In this embodiment, the outline of the plurality of first exposure patterns 410 includes: a plurality of first inner exposure segments (not shown) located within the critical exposure area SK and corresponding to the plurality of first inner segments 312a, and a plurality of first outer exposure segments (not shown) located outside the critical exposure area SK and corresponding to the plurality of first outer segments 312b.

[0089] In this embodiment, the inner edge placement error parameter E of any first exposure pattern 410 is obtained. in The method includes: obtaining the edge placement error (EPE) of each first inner exposure segment of the arbitrary first exposure pattern 410. in Determine all edge placement errors (EPE) of the arbitrary first exposure pattern 410. in The sum of squares yields the inner edge placement error parameter E of the arbitrary first exposure pattern 410. in Therefore, the placement error parameter E of the inner edge is achieved. in The acquisition of.

[0090] Specifically, when the total edge placement error EPE in When the number is n, the placement error parameter of the inner edge of any first exposure pattern 410 Both n and i are natural numbers.

[0091] In this embodiment, the placement error parameter E of the outer edge of any first exposure pattern 410 is obtained. out The method includes: obtaining the edge placement error (EPE) of each first outer exposure segment of the arbitrary first exposure pattern 410. out Determine all m edge placement errors (EPE) of the arbitrary first exposure pattern 410. out The sum of squares yields the outer edge placement error parameter E of the arbitrary first exposure pattern 410. out Therefore, the placement error parameter E of the outer edge is achieved. out The acquisition of.

[0092] Specifically, when the total edge placement error EPE out When the number is m, the placement error parameter of the outer edge of the arbitrary first exposure pattern 410 Both m and j are natural numbers.

[0093] In this embodiment, since the contours of several first graphics 310 are cut using several intersection points between the contour of each first graphic 310 and the boundary of the key area K as the cutting origin 311, it can be ensured that no first segment 312 spanning the key area K is formed. Therefore, the inner edge placement error parameter E can be easily and accurately obtained. in and the outer edge placement error parameter E out .

[0094] Please refer to Figure 10 Several first segments 312 are offset to form a second version 500.

[0095] Since the key region K is obtained in the first layout 300, and the outlines of each first graphic 310 are used as several intersection points with the boundary of the key region K as cutting origins 311 to cut the outlines of several first graphics 310 to form several first segments 312, the correlation between the lengths of the first segments 312 inside and outside the key region K is small when cutting the outlines inside and outside the key region K. Therefore, not only is the length of the first segments 312 inside and outside the key region K well controllable, but the length of the first segments 312 near the boundary of the key region K is also easy to reach the expected length (Spec). Furthermore, the rules for cutting the outlines are simpler. In addition, when offsetting several first segments 312, the accuracy of edge selection can be improved. As a result, the outline convergence effect of the exposed graphic formed after the exposure processing of the second layout 500 is good, and it can get closer to or achieve the convergence target, thereby improving the efficiency and accuracy of optical proximity correction.

[0096] The second version 500 includes a plurality of second figures 510 corresponding to a plurality of first figures 310.

[0097] In this embodiment, several first segments 312 are offset based on the edge placement error data of the first exposure pattern 400.

[0098] Specifically, the method for offsetting a plurality of first segments 312 based on the edge placement error data of the first exposure pattern 400 includes: when the edge placement error parameter MSE of any first exposure pattern 410 exceeds a preset MSE range, the plurality of first segments 312 corresponding to the arbitrary first exposure pattern are offset according to the edge placement error parameter MSE of the arbitrary first exposure pattern 410; when the edge placement error parameter MSE of each first exposure pattern 410 is within the preset edge placement error parameter range, the first pattern 300 is used as the second pattern 500 (i.e., the plurality of first segments 312 are not offset).

[0099] Wherein, the plurality of first segments 312 corresponding to any first exposure pattern 410 refers to the plurality of first segments 312 included in the outline of the first pattern 310 corresponding to any first exposure pattern 410.

[0100] In this embodiment, since the edge placement error parameter MSE = W of any first exposure pattern 410 in ×E in +W out ×E out The first weighting coefficient W in Greater than the second weighting coefficient W out Furthermore, the method for offsetting several first segments 312 includes: when the edge placement error parameter (MSE) of any first exposure pattern 410 exceeds a preset edge placement error parameter range, offsetting several first segments 312 corresponding to the arbitrary first exposure pattern according to the edge placement error parameter (MSE) of the arbitrary first exposure pattern 410; when the edge placement error parameter (MSE) of each first exposure pattern 410 is within the preset MSE range, then the first pattern 300 is used as the second pattern 500. Therefore, the first pattern 310 that needs to be offset can be determined more accurately, thereby further improving the correction efficiency while ensuring the accuracy of optical proximity correction.

[0101] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An optical proximity correction method, characterized in that, include: A target map is provided, the target map including a plurality of target graphics, wherein the target map includes a first area and a second area arranged along a first direction, the target graphics extend in a second direction, the first direction and the second direction are perpendicular to each other, a plurality of target graphics are located in the first area, a plurality of target graphics are located in the second area, and, in the first direction, the spacing between adjacent target graphics in the first area is less than the spacing between any target graphic in the second area and the boundary of the second area. The contours of several target graphics are compensated and edge-shifted to form a first layout; wherein, the method of compensating and edge-shifting the contours of several target graphics includes: offsetting the edges of the contours of several target graphics that are parallel to the first direction in a second direction to increase the length of the target graphics in the second direction, and wherein, in the offset, the offset distance of the edge of the target graphics in the second region is greater than the offset distance of the edge of the target graphics in the first region. A key area is obtained from a first map, which includes several first graphics, and the first graphics are partially located within the key area. Using the intersection points of the outline of each first graphic with the boundary of the key area as the cutting origin, the outlines of the first graphics are cut to form several first segments. Several segments of the first image are offset to form the second image.

2. The optical proximity correction method as described in claim 1, characterized in that, Also includes: The first map is exposed to obtain the first exposed map; Obtain the edge placement error data of the first exposure layout; The method for offsetting several first segments further includes: offsetting several first segments based on edge placement error data of the first exposure pattern.

3. The optical proximity correction method as described in claim 2, characterized in that, The first exposure layout includes a plurality of first exposure patterns corresponding to a plurality of first patterns, and a key exposure area corresponding to the key area; and the edge placement error data of the first exposure layout includes edge placement error parameters of each first exposure pattern. The method for obtaining the edge placement error parameters of each first exposure pattern includes: obtaining the inner edge placement error parameters of any first exposure pattern within the critical exposure area; Obtain the outer edge placement error parameter of the arbitrary first exposure pattern outside the critical exposure area; based on the inner edge placement error parameter and the outer edge placement error parameter of the arbitrary first exposure pattern, obtain the edge placement error parameter of the arbitrary first exposure pattern.

4. The optical proximity correction method as described in claim 3, characterized in that, Also includes: Obtain a first weighting coefficient corresponding to the inner edge placement error parameter, and a second weighting coefficient corresponding to the outer edge placement error parameter; The step of obtaining the edge placement error parameter of the arbitrary first exposure pattern based on the inner edge placement error parameter and the outer edge placement error parameter of the arbitrary first exposure pattern includes: determining the edge placement error parameter of the arbitrary first exposure pattern based on the inner edge placement error parameter, the outer edge placement error parameter, the first weighting coefficient, and the second weighting coefficient.

5. The optical proximity correction method as described in claim 4, characterized in that, The ratio of the first weighting coefficient to the second weighting coefficient is in the range of 1.5 to 4.

0.

6. The optical proximity correction method as described in claim 3, characterized in that, The plurality of first segments include a plurality of first inner segments located within the critical region, and the outline of the plurality of first exposure patterns includes a plurality of first inner exposure segments located within the critical exposure region and corresponding to the plurality of first inner segments. The method for obtaining the inner edge placement error parameter of any first exposure pattern includes: obtaining the edge placement error of each first inner exposure segment of the arbitrary first exposure pattern; determining the sum of squares of the edge placement errors of all first inner exposure segments of the arbitrary first exposure pattern to obtain the inner edge placement error parameter of the arbitrary first exposure pattern.

7. The optical proximity correction method as described in claim 6, characterized in that, The plurality of first segments further include a plurality of first outer segments located outside the critical area, and the outline of the plurality of first exposure patterns further includes a plurality of first outer exposure segments located outside the critical exposure area and corresponding to the plurality of first outer segments. The method for obtaining the outer edge placement error parameter of any first exposure pattern includes: obtaining the edge placement error of each first outer exposure segment of the arbitrary first exposure pattern; determining the sum of squares of the edge placement errors of all first outer exposure segments of the arbitrary first exposure pattern to obtain the outer edge placement error parameter of the arbitrary first exposure pattern.

8. The optical proximity correction method as described in claim 3, characterized in that, The method for offsetting several first segments to form a second pattern based on the edge placement error data of the first exposure pattern includes: when the edge placement error parameter of any first exposure pattern exceeds the preset edge placement error parameter range, offsetting several first segments corresponding to the arbitrary first exposure pattern according to the edge placement error parameter of the arbitrary first exposure pattern.

9. The optical proximity correction method as described in claim 8, characterized in that, The method of offsetting several first segments to form a second pattern based on the edge placement error data of the first exposure pattern further includes: when the edge placement error parameters of each first exposure pattern are all within the range of preset edge placement error parameters, the first pattern is used as the second pattern.

10. The optical proximity correction method as described in claim 1, characterized in that, The plurality of first segments include a plurality of first inner segments located within the critical region and a plurality of first outer segments located outside the critical region, wherein the length of any first inner segment is less than the length of any first outer segment.

11. The optical proximity correction method as described in claim 1, characterized in that, The method for obtaining key areas in the first layout includes: providing a layout of a preceding layer graphic, the layout of the preceding layer graphic including preceding key graphics; and determining key areas in the first layout based on the preceding key graphics.

12. The optical proximity correction method as described in claim 1, characterized in that, The method for obtaining the first layout includes: performing an exposure process on the target layout to obtain several exposed patterns; performing an etching process using the several exposed patterns as masks to obtain several etched patterns; performing post-etching detection on the several etched patterns based on the several target patterns to obtain etching deviation data; and performing edge-shifting compensation processing on the contours of the several target patterns based on the etching deviation data to form the first layout.

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