Optical proximity correction method and system, mask, equipment, storage medium and computer program product

Abstract

The invention discloses an optical proximity correction method and system, a mask, equipment, a storage medium and a computer program product, and the method comprises the steps: obtaining a first graph and a second graph of which the first distance is greater than a safety distance based on a rule that the end part of the first graph and the end part of the second graph have the safety distance in a first direction, taking the obtained first graph as a to-be-corrected graph; the end of the to-be-corrected graph is subjected to one or more times of extension processing in the first direction, a corrected graph is formed, the corrected graph formed in the last time of extension processing serves as a final corrected graph, and the second distance between the end of the final corrected graph and the end of the second graph in the first direction is smaller than or equal to the safety distance. The probability of bridging of the adjacent first patterns protruding out of the end of the second pattern at the end position can be reduced, and the process window of the photoetching process is enlarged.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and more particularly to an optical proximity correction method and system, a photomask, an apparatus and a storage medium, and a computer program product. 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 a semiconductor product that meets design requirements. The photolithography process includes an exposure step and a subsequent development step. In the exposure step, light passes through the transparent areas of the photomask and shines onto the silicon wafer coated with photoresist. The photoresist undergoes a chemical reaction under the light. 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. After the photolithography process, an etching step is usually performed. This involves etching the silicon wafer based on the photolithographic pattern formed by the photoresist layer, further transferring the photomask pattern onto the silicon wafer.

[0003] As semiconductor technology advances towards advanced processes and the critical dimensions of patterns shrink, back-end metal layers are formed using multiple exposure processes. Adjacent metal layers are separated by sidewall layers. After the first metal layer is formed through one exposure process, the second metal layer is formed on both sides of the first metal layer through another exposure process. The second metal layer that is directly opposite the first metal layer can be accurately transferred to the wafer. However, since there is no sidewall layer to block the adjacent second metal layers that protrude from the first metal layer, there is a risk of mutual bridging. Summary of the Invention

[0004] The problem solved by the embodiments of the present invention is to provide an optical proximity correction method and system, a photomask, an apparatus and a storage medium, and a computer program product, which is beneficial to improving the product yield of semiconductor structures.

[0005] To address the aforementioned problems, embodiments of the present invention provide an optical proximity correction method, comprising: providing an initial layout, the initial layout including a plurality of first graphics and second graphics located between adjacent first graphics, the first graphics extending along a first direction and arranged in parallel at intervals along a second direction, the second graphics extending along the first direction and arranged in parallel at intervals along the second direction, the first direction being perpendicular to the second direction, the ends of the first graphics protruding beyond the ends of the second graphics, and the ends of the first graphics and the ends of the second graphics having a first distance in the first direction; based on the rule that the ends of the first graphics and the ends of the second graphics have a safe distance in the first direction, obtaining first graphics and second graphics with a first distance greater than the safe distance, and using the obtained first graphics as graphics to be corrected; performing one or more extension processes along the first direction on the ends of the graphics to be corrected to form a corrected graphics, and using the corrected graphics formed in the last extension process as the final corrected graphics, wherein the second distance between the ends of the final corrected graphics and the ends of the second graphics in the first direction is less than or equal to the safe distance.

[0006] Optionally, the extension process includes: extending the end of the graphic to be corrected along a first direction by a first fixed value to form a corrected graphic; after forming the corrected graphic, obtaining a second distance between the end of the corrected graphic and the end of the first graphic in the first direction; comparing the second distance with a safety distance, and when the second distance is greater than the safety distance, using the corrected graphic as the graphic to be corrected in the next extension process, and when the second distance is less than or equal to the safety distance, using the corrected graphic as the final corrected graphic.

[0007] Optionally, in the step of providing the initial layout, the sides of the first and second graphics are further formed with a third graphic extending along a first direction, and the end of the third graphic is spaced apart from and directly opposite the end of the second graphic; based on the rule that the third distance between the end of the second graphic and the end of the third graphic directly opposite each other in the first direction has the minimum feature size, during the process of extending the end of the graphic to be corrected, the third distance between the end of the corrected graphic and the end of the third graphic directly opposite each other is greater than or equal to the minimum feature size.

[0008] Optionally, during the extension process, when the third distance is equal to the minimum feature size, the optical proximity correction method further includes: comparing the second distance with the safety distance; when the second distance is less than or equal to the safety distance, using the corrected image as the final corrected image; when the second distance is greater than the safety distance, obtaining the difference between the second distance and the safety distance, and using the difference as a reference value.

[0009] Optionally, after obtaining the reference value, the optical proximity correction method further includes: selecting any value greater than or equal to the reference value as a second fixed value based on the reference value; and retracting the end of the third graphic that is directly opposite the end of the graphic to be corrected along the first direction, wherein the retraction size of the retraction is the second fixed value.

[0010] Optionally, after the shrinkage process, the end of the graphic to be corrected is extended one last time, and the second fixed value is used as the extension value of the extension process.

[0011] Optionally, the step of obtaining the safety distance includes: based on a large amount of production data, including a first spacing between adjacent first solid patterns formed on a wafer by the first pattern, obtaining a distance in the first spacing that can support the separation of adjacent solid patterns, and using this distance as a safety value after etching; based on the portion of the first pattern protruding from the end of the second pattern as a protrusion, obtaining each second spacing between adjacent second solid patterns formed on the wafer after photolithography at different lengths of the protrusion in the first direction; based on the safety value after etching, the different lengths of the protrusion in the first direction, and each second spacing between adjacent second solid patterns, obtaining a second spacing equal to the safety value after etching, and the length of the protrusion in the first direction corresponding to the second spacing, and using the length of the protrusion in the first direction corresponding to the second spacing as the safety distance.

[0012] Optionally, the rule that the third distance between the ends of the second pattern and the ends of the third pattern facing each other in the first direction has a minimum feature size includes the minimum spacing between adjacent patterns supported by the photolithography process.

[0013] Optionally, the first graphic includes a metal line graphic; the second graphic includes a metal line graphic.

[0014] Accordingly, embodiments of the present invention provide an optical proximity correction system, comprising: a providing module for providing an initial layout, the initial layout including a plurality of first graphics and second graphics located between adjacent first graphics, the first graphics extending along a first direction and arranged in parallel at intervals along a second direction, the second graphics extending along the first direction and arranged in parallel at intervals along the second direction, the first direction being perpendicular to the second direction, the ends of the first graphics protruding beyond the ends of the second graphics, and the ends of the first graphics and the ends of the second graphics having a first distance in the first direction; a first acquiring module for acquiring first graphics and second graphics with a first distance greater than a safe distance based on a rule that the ends of the first graphics and the ends of the second graphics have a safe distance in the first direction, and using the acquired first graphics as graphics to be corrected; and an extending module for extending the ends of the graphics to be corrected one or more times along the first direction to form a corrected graphics, and using the corrected graphics formed in the last extending process as the final corrected graphics, wherein the second distance between the ends of the final corrected graphics and the ends of the second graphics in the first direction is less than or equal to the safe distance.

[0015] Optionally, in the initial layout provided by the providing module, the sides of the first and second graphics are further formed with a third graphic extending along the first direction, and the end of the third graphic is spaced apart from and directly opposite the end of the second graphic; the extension module, based on the rule that the third distance between the end of the second graphic and the end of the third graphic directly opposite each other in the first direction has the minimum feature size, corrects the third distance between the end of the graphic and the end of the third graphic to be greater than or equal to the minimum feature size.

[0016] Optionally, when the third distance is equal to the minimum feature size, the optical proximity correction system further includes: a first comparison unit, used to compare the second distance with the safety distance; when the second distance is less than or equal to the safety distance, the corrected image is used as the final corrected image; when the second distance is greater than the safety distance, the difference between the second distance and the safety distance is obtained, and the difference is used as a reference value.

[0017] Optionally, the optical proximity correction system further includes: a selection unit, used to select any value greater than or equal to the reference value as a second fixed value based on the reference value; and a retraction unit, used to retract the end of the third graphic that is directly opposite the end of the graphic to be corrected along a first direction, wherein the retraction dimension of the retraction process is the second fixed value.

[0018] Accordingly, embodiments of the present invention also provide a mask, including a plurality of first patterns and a second pattern located between adjacent first patterns, wherein the first and second patterns are set by the optical proximity correction method provided in embodiments of the present invention.

[0019] Optionally, the first graphic is used to define the metal wire pattern; the second graphic is used to define the metal wire pattern.

[0020] Accordingly, embodiments of the present invention also provide an apparatus including at least one memory and at least one processor, wherein the memory stores one or more computer instructions, and the one or more computer instructions are executed by the processor to implement the optical proximity correction method provided in the embodiments of the present invention.

[0021] Accordingly, embodiments of the present invention also provide a storage medium storing one or more computer instructions, which are used to implement the optical proximity correction method provided in the embodiments of the present invention.

[0022] Accordingly, embodiments of the present invention also provide a computer program product, including computer instructions, which, when executed by a processor, are used to implement the optical proximity correction method provided in embodiments of the present invention.

[0023] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0024] In the optical proximity correction method provided in this embodiment of the invention, the end of the pattern to be corrected is extended once or multiple times along a first direction to form a corrected pattern. The corrected pattern formed in the last extension process is taken as the final corrected pattern. The second distance between the end of the final corrected pattern and the end of the second pattern in the first direction is less than or equal to a safety distance. That is, by extending the end of the pattern to be corrected once or multiple times, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than the safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging at the end position of adjacent first patterns protruding from the end of the second pattern can be reduced. At the same time, by extending only the end of the pattern to be corrected once or multiple times, the size of the first pattern in the first direction can remain unchanged. Correspondingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern can also be increased, thereby improving the product yield of the semiconductor structure.

[0025] The optical proximity correction system provided in this embodiment of the invention involves an extension module extending the end of the pattern to be corrected one or more times along a first direction to form a corrected pattern. The corrected pattern formed in the last extension process is taken as the final corrected pattern. The second distance between the end of the final corrected pattern and the end of the second pattern in the first direction is less than or equal to a safety distance. In other words, by extending the end of the pattern to be corrected one or more times, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than the safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging at the end position of adjacent first patterns protruding from the end of the second pattern can be reduced. At the same time, by extending only the end of the pattern to be corrected one or more times, the size of the first pattern in the first direction can remain unchanged. Correspondingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern can also be increased, thereby improving the product yield of the semiconductor structure. Attached Figure Description

[0026] Figure 1 This is a flowchart of an embodiment of the optical proximity correction method of the present invention;

[0027] Figures 2 to 7 This is a schematic diagram of each step in one embodiment of the optical proximity correction method of the present invention;

[0028] Figure 8 This is a functional block diagram of an embodiment of the optical proximity correction system of the present invention;

[0029] Figure 9 This is a hardware structure diagram of an embodiment of the device provided by the present invention. Detailed Implementation

[0030] As is known from the background technology, after the first metal layer is formed by an exposure process, the second metal layer is formed on both sides of the first metal layer by another exposure process. The second metal layer that is directly opposite the first metal layer can be accurately transferred to the wafer. However, since there is no sidewall layer to block the adjacent second metal layers that protrude from the first metal layer, there is a risk of mutual bridging, which leads to a decrease in the product yield of the wafer.

[0031] To address the technical problem, embodiments of the present invention provide an optical proximity correction method. (Reference) Figure 1 The flowchart of an embodiment of the optical proximity correction method of the present invention is shown.

[0032] In this embodiment, the optical proximity correction method includes the following basic steps:

[0033] Step S1: Provide an initial layout, which includes a plurality of first graphics and second graphics located between adjacent first graphics. The first graphics extend along a first direction and are arranged in parallel at intervals along a second direction. The second graphics extend along the first direction and are arranged in parallel at intervals along the second direction. The first direction is perpendicular to the second direction. The end of the first graphics protrudes beyond the end of the second graphics, and the end of the first graphics and the end of the second graphics have a first distance in the first direction.

[0034] Step S2: Based on the rule that the ends of the first graphic and the ends of the second graphic have a safe distance in the first direction, obtain the first graphic and the second graphic whose first distance is greater than the safe distance, and use the obtained first graphic as the graphic to be corrected;

[0035] Step S3: After setting the first auxiliary graphic, obtain the adjacent main graphics in the graphic to be corrected that do not meet the photolithography process window limit requirements, and take the area between the adjacent main graphics as the prohibited area;

[0036] Step S4: Along the first direction, extend the end of the graphic to be corrected once or multiple times to form the corrected graphic, and take the corrected graphic formed in the last extension process as the final corrected graphic. The second distance between the end of the final corrected graphic and the end of the second graphic in the first direction is less than or equal to the safety distance.

[0037] In this embodiment of the invention, the end of the pattern to be corrected is extended once or multiple times along a first direction to form a corrected pattern. The corrected pattern formed in the last extension process is taken as the final corrected pattern. The second distance between the end of the final corrected pattern and the end of the second pattern in the first direction is less than or equal to a safety distance. That is, by extending the end of the pattern to be corrected once or multiple times, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than the safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging at the end position of adjacent first patterns protruding from the end of the second pattern can be reduced. At the same time, by extending only the end of the pattern to be corrected once or multiple times, the size of the first pattern in the first direction can remain unchanged. Accordingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern can also be increased, thereby improving the product yield of the semiconductor structure.

[0038] To make the above-mentioned objects, features and advantages 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.

[0039] Figures 2 to 7 This is a schematic diagram of each step in one embodiment of the optical proximity correction method of the present invention.

[0040] refer to Figure 2 Step S1: Provide an initial layout 100, which includes a plurality of first graphics 101 and second graphics 102 located between adjacent first graphics 101. The first graphics 101 are arranged along a first direction (e.g., ...). Figure 2 Extending along the X direction (as shown) and along the second direction (as shown) Figure 2 The first graphic 101 is arranged in parallel at intervals (as shown in the Y direction). The second graphic 102 extends along the first direction and is arranged in parallel at intervals along the second direction. The first direction is perpendicular to the second direction. The end of the first graphic 101 protrudes beyond the end of the second graphic 102, and the end of the first graphic 101 and the end of the second graphic 102 have a first distance L1 in the first direction.

[0041] Specifically, the first pattern 101 and the second pattern 102 are used to make a mask for use in the photolithography process. The mask can expose the photoresist on the wafer to form photoresist patterns for each chip area on the wafer. The photoresist patterns can be used to etch the chip areas of the wafer, thereby forming device structures such as trenches, gates, metal lines or conductive plugs in the chip areas of the wafer.

[0042] As an example, in a process of exposing photoresist on a wafer using a mask, the first pattern 101 and the second pattern 102 are set on different masks, so that the photoresist on the wafer is exposed using different masks respectively.

[0043] Specifically, the first pattern 101 is disposed on the first mask, and the second pattern 102 is disposed on the second mask. In the process of exposing the photoresist on the wafer using the mask, the photoresist on the wafer is first exposed using the second mask, and then exposed using the first mask.

[0044] In this embodiment, both the first graphic 101 and the second graphic 102 include metal layer patterns.

[0045] In other embodiments, the first and second patterns may also be fin patterns or gate structure patterns.

[0046] In this embodiment, during the step of providing the initial layout 100, a third graphic 110 extending along a first direction is further formed on the side of the first graphic 101 and the second graphic 102, and the end of the third graphic 110 is spaced apart from and directly opposite the end of the second graphic 102.

[0047] Specifically, the third pattern 110 is used to make a photomask for use in the photolithography process. The photomask can be used to expose the photoresist on the wafer, and the third pattern 110 and the second pattern 102 are set on the same photomask.

[0048] refer to Figure 3 Based on the rule that the ends of the first graphic 101 and the ends of the second graphic 102 have a safe distance D1 in the first direction, the first graphic 101 and the second graphic 102 with a first distance L1 greater than the safe distance D1 are obtained, and the obtained first graphic 101 is used as the graphic 104 to be corrected.

[0049] It should be noted that by obtaining the first graphic 101 and the second graphic 102, where the first distance L1 is greater than the safety distance D1, the first graphic 101 that needs to be corrected can be defined, which is beneficial for subsequent correction of the defined first graphic 101.

[0050] It should also be noted that the rule that the ends of the first pattern 101 and the ends of the second pattern 102 have a safe distance D1 in the first direction means that in the process of exposing the photoresist on the wafer with the first pattern 101 as a mask, in order to reduce the probability of bridging between adjacent first patterns 101 that protrude from the ends of the second pattern 102, the ends of the first pattern 101 and the ends of the second pattern 102 need to satisfy a safe distance D1 in the first direction.

[0051] In this embodiment, the step of obtaining the safety distance D1 includes: based on a large amount of production data, including the first spacing between adjacent first solid patterns formed by the first pattern 101 on the wafer, obtaining the distance in the first spacing that can support the separation of adjacent solid patterns, and using this distance as the safety value after etching; based on the portion of the first pattern 101 protruding from the end of the second pattern 102 as a protrusion, obtaining each second spacing between adjacent second solid patterns formed on the wafer after photolithography at different lengths of the protrusion in the first direction; based on the safety value after etching, the different lengths of the protrusion in the first direction, and each second spacing between adjacent second solid patterns, obtaining a second spacing equal to the safety value after etching, and the length of the protrusion in the first direction corresponding to the second spacing, and using the length of the protrusion in the first direction corresponding to the second spacing as the safety distance D1.

[0052] Specifically, by obtaining the safety distance D1, in the subsequent process of extending the graphic 104 to be corrected, the distance between the end of the corrected graphic and the end of the first graphic 101 in the first direction can be obtained and compared with the safety distance D1 to determine whether the extension process is the last extension process, and then the corrected graphic of the last extension process is taken as the final corrected graphic.

[0053] refer to Figures 4 to 7 Along the first direction, the end of the pattern 104 to be corrected is extended once or multiple times to form the corrected pattern 106, and the corrected pattern 106 formed in the last extension process is taken as the final corrected pattern 108. The second distance L2 between the end of the final corrected pattern 108 and the end of the second pattern 102 in the first direction is less than or equal to the safety distance D1.

[0054] It should be noted that the end of the pattern to be corrected 104 is extended one or more times to form the corrected pattern 106, and the corrected pattern 106 formed in the last extension process is taken as the final corrected pattern 108. The second distance L2 between the end of the final corrected pattern 108 and the end of the second pattern 102 in the first direction is less than or equal to the safety distance D1. That is, by extending the end of the pattern to be corrected 104 one or more times, the second distance L2 between the end of the final corrected pattern 108 and the end of the first pattern 101 in the first direction can be less than the safety distance D1. In the subsequent process of using the first pattern 101 and the second pattern 102 as photomasks to form a solid pattern on the wafer, the probability of bridging at the end position of the adjacent first pattern 101 protruding from the end of the second pattern 102 can be reduced.

[0055] It should also be noted that by performing one or more extension processes only on the end of the pattern 104 to be corrected, the size of the first pattern 101 in the first direction can remain unchanged. Accordingly, in the subsequent process of using the first pattern 101 as a photomask to form a solid pattern on the wafer, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern 101 can also be increased, thereby improving the product yield of the semiconductor structure.

[0056] In this embodiment, the extension process includes: extending the end of the pattern 104 to be corrected along the first direction by a first fixed value to form a corrected pattern 106; after forming the corrected pattern 106, obtaining a second distance L2 between the end of the corrected pattern 106 and the end of the first pattern 101 in the first direction; comparing the second distance L2 with a safety distance D1, and when the second distance L2 is greater than the safety distance D1, using the corrected pattern 106 as the pattern to be corrected in the next extension process, and when the second distance L2 is less than or equal to the safety distance D1, using the corrected pattern 106 as the final corrected pattern 108.

[0057] In this embodiment, based on the rule that the third distance between the end of the second graphic 102 and the end of the third graphic 110 facing each other in the first direction has the minimum feature size, during the process of extending the end of the graphic 104 to be corrected, the third distance between the end of the corrected graphic 106 and the end of the third graphic 110 facing each other is greater than or equal to the minimum feature size.

[0058] As an example, the rule that the third distance between the end of the second pattern 102 and the end of the third pattern 110, which are directly opposite each other in the first direction, has a minimum feature size includes the minimum spacing between adjacent patterns supported by the photolithography process.

[0059] It should be noted that, according to the exposure limit of the lithography process, the minimum spacing between adjacent patterns supported by the lithography process is the minimum feature size. That is to say, the third distance between the end of the second pattern 102 and the end of the third pattern 110 facing each other in the first direction is greater than or equal to the minimum feature size. In the process of forming a solid pattern on the wafer using the second pattern 102 and the third pattern 110 as masks, it is possible to transfer the second pattern 102 and the third pattern 110 to the wafer, so that the pattern structure of the semiconductor structure meets the design requirements.

[0060] In this embodiment, during the extension process, when the third distance is equal to the minimum feature size, the optical proximity correction method further includes: comparing the second distance L2 with the safety distance D1, and when the second distance L2 is less than or equal to the safety distance D1, using the corrected pattern 106 as the final corrected pattern 108.

[0061] Specifically, by comparing the second distance L2 with the safety distance D1, it can be determined whether the current extension process is the last extension process.

[0062] As an example, when the second distance L2 is less than or equal to the safety distance D1, the corrected graph 106 is used as the final corrected graph 108.

[0063] In other words, when the second distance L2 is less than or equal to the safety distance D1, the probability of bridging between adjacent first patterns 101 protruding from the second pattern 102 can be reduced during the subsequent process of forming a solid pattern on the wafer using the first pattern 101 as a mask.

[0064] In this embodiment, when the second distance L2 is greater than the safety distance D1, the difference between the second distance L2 and the safety distance D1 is obtained, and the difference is used as the reference value.

[0065] It should be noted that the second distance L2 is greater than the safety distance D1, which means that in the subsequent process of forming a solid pattern on the wafer using the first pattern 101 as a mask, the probability of bridging between adjacent first patterns 101 protruding from the second pattern 102 is still relatively high. Therefore, it is necessary to continue to extend the pattern 104 to be corrected. Thus, by obtaining the difference between the second distance L2 and the safety distance D1, the reference value is used as the reference value for the subsequent shrinkage process, so that after the shrinkage process, an extension area can be provided for the extension process.

[0066] In this embodiment, after obtaining the reference value, the optical proximity correction method further includes: selecting any value greater than or equal to the reference value as a second fixed value D2 based on the reference value; and retracting the end of the third graphic 110 that is directly opposite the end of the graphic 104 to be corrected along the first direction, wherein the retraction size of the retraction is the second fixed value D2.

[0067] Specifically, by retracting the end of the third graphic 110 along the first direction, the distance between the third graphic 110 and the second graphic 102 can be increased, making the third distance between the third graphic 110 and the second graphic 102 greater than or equal to the minimum feature size, and providing space for subsequent extension processing.

[0068] In this embodiment, after the retraction process, the end of the pattern 104 to be corrected is extended for the last time, and the second fixed value D2 is used as the extension value of the extension process.

[0069] Specifically, by using the second fixed value D2 as the extension value for the extension process, the second distance L2 between the end of the final corrected pattern 108 and the end of the first pattern 101 in the first direction can be less than or equal to the safety distance D1. This reduces the probability of bridging at the end position of adjacent first patterns 101 protruding from the end of the second pattern 102 during the subsequent process of forming a solid pattern on the wafer using the first pattern 101 as a photomask.

[0070] Accordingly, the present invention also provides an optical proximity correction system. Figure 8 This is a functional block diagram of the optical proximity correction system of the present invention.

[0071] An optical proximity correction system includes: a providing module 201 for providing an initial layout, the initial layout including a plurality of first graphics and second graphics located between adjacent first graphics, the first graphics extending along a first direction and arranged in parallel at intervals along a second direction, the second graphics extending along the first direction and arranged in parallel at intervals along the second direction, the first direction being perpendicular to the second direction, the ends of the first graphics protruding beyond the ends of the second graphics, and the ends of the first graphics and the ends of the second graphics having a first distance in the first direction; a first acquiring module 202 for acquiring first graphics and second graphics with a first distance greater than a safe distance based on a rule that the ends of the first graphics and the ends of the second graphics have a safe distance in the first direction, and using the acquired first graphics as graphics to be corrected; and an extending module 203 for extending the ends of the graphics to be corrected one or more times along the first direction to form a corrected graphics, and using the corrected graphics formed in the last extending process as the final corrected graphics, wherein the second distance between the ends of the final corrected graphics and the ends of the second graphics in the first direction is less than or equal to the safe distance.

[0072] It should be noted that the extension module 203 extends the end of the pattern to be corrected one or more times along the first direction to form a corrected pattern, and the corrected pattern formed in the last extension process is taken as the final corrected pattern. The second distance between the end of the final corrected pattern and the end of the second pattern in the first direction is less than or equal to the safety distance. That is, by extending the end of the pattern to be corrected one or more times, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than the safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging between adjacent first patterns protruding from the end of the second pattern can be reduced. At the same time, by extending only the end of the pattern to be corrected one or more times, the size of the first pattern in the first direction can remain unchanged. Accordingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern can also be increased, thereby improving the product yield of the semiconductor structure.

[0073] Specifically, module 201 is used to provide a first pattern and a second pattern. The first pattern and the second pattern are used to make a mask for use in the photolithography process. The mask can be used to expose the photoresist on the wafer to form photoresist patterns of each chip area on the wafer. The photoresist patterns can be used to etch the chip areas of the wafer, thereby forming device structures such as trenches, gates, metal lines or conductive plugs in the chip areas of the wafer.

[0074] As an example, in a process of exposing photoresist on a wafer using a mask, the first pattern and the second pattern are set on different masks, so that the photoresist on the wafer is exposed using different masks respectively.

[0075] Specifically, the first pattern is set on the first mask, and the second pattern is set on the second mask. In the process of exposing the photoresist on the wafer using the mask, the photoresist on the wafer is first exposed using the second mask, and then exposed using the first mask.

[0076] In this embodiment, both the first and second patterns include metal layer patterns.

[0077] In other embodiments, the first and second patterns may also be fin patterns or gate structure patterns.

[0078] In this embodiment, in the initial layout of the module 201, a third shape extending along a first direction is formed on the side of the first shape and the second shape, and the end of the third shape is spaced apart from and directly opposite the end of the second shape.

[0079] Specifically, the third pattern is used to create a photomask for the photolithography process. The photomask can be used to expose the photoresist on the wafer, and the third pattern and the second pattern are set on the same photomask.

[0080] The first acquisition module 202 can define the first graphic that needs to be corrected by acquiring the first graphic and the second graphic whose first distance is greater than the safe distance, which is beneficial for subsequent correction of the defined first graphic.

[0081] It should be noted that the rule that the ends of the first pattern and the ends of the second pattern have a safe distance in the first direction means that in the process of exposing the photoresist on the wafer with the first pattern as a mask, in order to reduce the probability of bridging between adjacent first patterns that protrude from the ends of the second pattern, the ends of the first pattern and the ends of the second pattern need to satisfy a safe distance in the first direction.

[0082] In this embodiment, the step of obtaining the safety distance includes: based on a large amount of production data, including the first spacing between adjacent first solid patterns formed by the first pattern on the wafer, obtaining the distance in the first spacing that can support the separation of adjacent solid patterns, and using this distance as the safety value after etching; based on the portion of the first pattern protruding from the end of the second pattern as a protrusion, obtaining each second spacing between adjacent second solid patterns formed on the wafer after photolithography at different lengths of the protrusion in the first direction; based on the safety value after etching, the different lengths of the protrusion in the first direction, and each second spacing between adjacent second solid patterns, obtaining a second spacing equal to the safety value after etching, and the length of the protrusion in the first direction corresponding to the second spacing, and using the length of the protrusion in the first direction corresponding to the second spacing as the safety distance.

[0083] Specifically, by obtaining a safety distance, in the subsequent process of extending the graphic to be corrected, the distance between the end of the corrected graphic and the end of the first graphic in the first direction can be obtained and compared with the safety distance to determine whether the extension process is the last extension process, and then the corrected graphic of the last extension process is taken as the final corrected graphic.

[0084] It should be noted that the extension module 203 extends the end of the pattern to be corrected one or more times along the first direction to form a corrected pattern, and the corrected pattern formed in the last extension process is taken as the final corrected pattern. The second distance between the end of the final corrected pattern and the end of the second pattern in the first direction is less than or equal to the safety distance. That is, by extending the end of the pattern to be corrected one or more times, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than the safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging between adjacent first patterns protruding from the end of the second pattern can be reduced. At the same time, by extending only the end of the pattern to be corrected one or more times, the size of the first pattern in the first direction can remain unchanged. Accordingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, the process difficulty can be reduced, and the process window for forming other solid patterns (such as interconnect vias) on the solid pattern formed by the first pattern can also be increased, thereby improving the product yield of the semiconductor structure.

[0085] In this embodiment, the extension module 203 includes: an extension unit, used to extend the end of the graphic to be corrected along a first direction by a first fixed value to form a corrected graphic; a first acquisition unit, used to acquire, after forming the corrected graphic, a second distance between the end of the corrected graphic and the end of the first graphic in a first direction; and a second comparison unit, used to compare the second distance with a safety distance, wherein when the second distance is greater than the safety distance, the corrected graphic is used as the graphic to be corrected in the next extension process, and when the second distance is less than or equal to the safety distance, the corrected graphic is used as the final corrected graphic.

[0086] In this embodiment, the extension module 203, based on the rule that the third distance between the end of the second graphic and the end of the third graphic facing each other in the first direction has the minimum feature size, corrects the third distance between the end of the graphic and the end of the third graphic to be greater than or equal to the minimum feature size.

[0087] As an example, the rule that the third distance between the ends of the second pattern and the ends of the third pattern, which are directly opposite each other in the first direction, has a minimum feature size includes the minimum spacing between adjacent patterns supported by the photolithography process.

[0088] It should be noted that, according to the exposure limit of the lithography process, the minimum spacing between adjacent patterns supported by the lithography process is the minimum feature size. That is to say, the third distance between the ends of the second pattern and the ends of the third pattern facing each other in the first direction is greater than or equal to the minimum feature size. In the process of forming a solid pattern on the wafer using the second and third patterns as masks, it is possible to transfer the second and third patterns to the wafer, so that the pattern structure of the semiconductor structure meets the design requirements.

[0089] In this embodiment, when the third distance is equal to the minimum feature size, the optical proximity correction system further includes: a first comparison unit, used to compare the second distance with the safety distance; when the second distance is less than or equal to the safety distance, the corrected image is used as the final corrected image; when the second distance is greater than the safety distance, the difference between the second distance and the safety distance is obtained, and the difference is used as a reference value.

[0090] Specifically, by comparing the second distance with the safety distance, it is possible to determine whether the current extension process is the last extension process.

[0091] As an example, when the second distance is less than or equal to the safety distance, the corrected graph is used as the final corrected graph.

[0092] In other words, when the second distance is less than or equal to the safety distance, the probability of bridging between adjacent first patterns protruding from the second pattern can be reduced during the subsequent process of forming a solid pattern on the wafer using the first pattern as a mask.

[0093] In this embodiment, when the second distance is greater than the safe distance, the difference between the second distance and the safe distance is obtained, and the difference is used as a reference value.

[0094] It should be noted that the second distance is greater than the safety distance, which means that in the subsequent process of forming a solid pattern on the wafer using the first pattern as a mask, the probability of bridging between adjacent first patterns protruding from the second pattern is still relatively high. Therefore, it is necessary to continue to extend the pattern to be corrected. Thus, by obtaining the difference between the second distance and the safety distance, the benchmark value is used as a reference value for the subsequent shrinkage process, thereby providing an extension area for the extension process after the shrinkage process.

[0095] In this embodiment, the optical proximity correction system further includes: a selection unit, used to select any value greater than or equal to the reference value as a second fixed value based on the reference value; and a retraction unit, used to retract the end of the third graphic that is directly opposite the end of the graphic to be corrected along a first direction, wherein the retraction size of the retraction process is the second fixed value.

[0096] Specifically, by retracting the end of the third graphic along the first direction, the retraction unit can increase the distance between the third graphic and the second graphic, making the third distance between the third graphic and the second graphic greater than or equal to the minimum feature size, and providing space for subsequent extension processing.

[0097] In this embodiment, after the shrinkage process, the end of the graphic to be corrected is extended for the last time, and the second fixed value is used as the extension value of the extension process.

[0098] Specifically, by using the second fixed value as the extension value for the extension process, the second distance between the end of the final corrected pattern and the end of the first pattern in the first direction can be less than or equal to the safe distance. This reduces the probability of bridging at the end position of adjacent first patterns protruding from the end of the second pattern during the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask.

[0099] Accordingly, embodiments of the present invention also provide a mask, including a plurality of first patterns and a second pattern located between adjacent first patterns, wherein the first and second patterns are set by the optical proximity correction method provided in embodiments of the present invention.

[0100] As described above, in the optical proximity correction method provided in this embodiment, by performing one or more extension processes on the end of the pattern to be corrected, the second distance between the end of the finally corrected pattern and the end of the first pattern in the first direction can be less than a safety distance. In the subsequent process of forming a solid pattern on the wafer using the first and second patterns as photomasks, the probability of bridging between adjacent first patterns protruding from the end of the second pattern at the end position can be reduced. Simultaneously, by performing one or more extension processes only on the end of the pattern to be corrected, the size of the first pattern in the first direction can remain unchanged. Correspondingly, in the subsequent process of forming a solid pattern on the wafer using the first pattern as a photomask, the process window of the photolithography process can be increased, reducing process difficulty. It also increases the process window for forming other solid patterns (e.g., interconnect vias) on the solid pattern formed by the first pattern, thereby improving the product yield of the semiconductor structure. Therefore, the mask provided in this embodiment of the invention can improve the product yield of semiconductor structures and reduce the probability of bridging between patterns on the wafer.

[0101] The first pattern is used to define the metal line pattern, and the second pattern is used to define the metal line pattern. Accordingly, after performing photolithography on the wafer using the mask provided in this embodiment, the resulting metal line pattern has high pattern quality and high yield.

[0102] This invention also provides a device that can acquire the optical proximity correction method described above in the form of a loading program to implement the optical proximity correction method provided in this invention. An optional hardware structure of the terminal device provided in this invention can be as follows: Figure 9 As shown, it includes: at least one processor 01, at least one communication interface 02, at least one memory 03, and at least one communication bus 04.

[0103] In this embodiment, the number of processor 01, communication interface 02, memory 03, and communication bus 04 is at least one, and the processor 01, communication interface 02, and memory 03 communicate with each other through communication bus 04. Communication interface 02 can be an interface of a communication module for network communication, such as the interface of a GSM module. Processor 01 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. Memory 03 may include high-speed RAM and may also include non-volatile memory (NVM), such as at least one disk storage device. Memory 03 stores one or more computer instructions, which are executed by processor 01 to implement the optical proximity correction method provided in this embodiment of the present invention.

[0104] It should be noted that the aforementioned terminal device may also include other devices (not shown) that may not be essential to understanding the content disclosed in the embodiments of the present invention; given that these other devices may not be essential for understanding the content disclosed in the embodiments of the present invention, the embodiments of the present invention will not describe them one by one.

[0105] This invention also provides a storage medium storing one or more computer instructions for implementing the optical proximity correction method provided in this invention.

[0106] Embodiments of the present invention can be implemented by various means, such as hardware, firmware, software, or combinations thereof. In a hardware configuration, the method according to an exemplary embodiment of the present invention can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc. In a firmware or software configuration, embodiments of the present invention can be implemented in the form of modules, processes, functions, etc. Software code can be stored in memory units and executed by a processor. The memory units are located inside or outside the processor and can send data to and receive data from the processor via various known means.

[0107] Accordingly, a computer program product includes computer instructions, which, when executed by a processor, are used to implement the optical proximity correction method provided in the embodiments of the present invention.

[0108] 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: An initial layout is provided, the initial layout including a plurality of first graphics and second graphics located between adjacent first graphics, the first graphics extending along a first direction and arranged in parallel at intervals along a second direction, the second graphics extending along the first direction and arranged in parallel at intervals along the second direction, the first direction being perpendicular to the second direction, the end of the first graphics protruding beyond the end of the second graphics, and the end of the first graphics and the end of the second graphics having a first distance in the first direction. Based on the rule that the ends of the first graphic and the ends of the second graphic have a safe distance in the first direction, a first graphic and a second graphic whose first distance is greater than the safe distance are obtained, and the obtained first graphic is used as the graphic to be corrected. Along the first direction, the end of the graphic to be corrected is extended once or multiple times to form a corrected graphic, and the corrected graphic formed in the last extension process is taken as the final corrected graphic. The second distance between the end of the final corrected graphic and the end of the second graphic in the first direction is less than or equal to the safety distance.

2. The optical proximity correction method as described in claim 1, characterized in that, The extension process includes: extending the end of the graphic to be corrected along the first direction by a first fixed value to form a corrected graphic; After forming the corrected shape, the second distance between the end of the corrected shape and the end of the first shape in the first direction is obtained; The second distance is compared with the safety distance. When the second distance is greater than the safety distance, the corrected graphic is used as the graphic to be corrected in the next extension process. When the second distance is less than or equal to the safety distance, the corrected graphic is used as the final corrected graphic.

3. The optical proximity correction method as described in claim 1, characterized in that, In the step of providing the initial layout, a third shape extending along the first direction is further formed on the side of the first shape and the second shape, and the end of the third shape is spaced apart from and directly opposite the end of the second shape; Based on the rule that the third distance between the end of the second graphic and the end of the third graphic facing each other in the first direction has a minimum feature size, during the process of extending the end of the graphic to be corrected, the third distance between the end of the corrected graphic and the end of the third graphic facing each other is greater than or equal to the minimum feature size.

4. The optical proximity correction method as described in claim 3, characterized in that, During the extension process, when the third distance equals the minimum feature size, the optical proximity correction method further includes: The second distance is compared with the safety distance. When the second distance is less than or equal to the safety distance, the corrected image is taken as the final corrected image. When the second distance is greater than the safe distance, the difference between the second distance and the safe distance is obtained, and the difference is used as a reference value.

5. The optical proximity correction method as described in claim 4, characterized in that, After obtaining the reference value, the optical proximity correction method further includes: selecting any value greater than or equal to the reference value as a second fixed value based on the reference value; The end of the third graphic that is directly opposite the end of the graphic to be corrected is retracted along the first direction, and the retraction size of the retraction process is a second fixed value.

6. The optical proximity correction method as described in claim 5, characterized in that, After the retraction process is performed, the end of the graphic to be corrected is extended one last time, and the second fixed value is used as the extension value of the extension process.

7. The optical proximity correction method as described in claim 1, characterized in that, The step of obtaining the safety distance includes: based on a large amount of production data, the production data including the first spacing between adjacent first physical patterns formed by the first pattern on the wafer, obtaining the distance in the first spacing that can support the separation of adjacent physical patterns, and using the distance as a safety value after etching; Based on the portion of the first pattern protruding from the end of the second pattern as the protrusion, the second spacing between adjacent second solid patterns formed on the wafer after photolithography is obtained at different lengths of the protrusion in the first direction. Based on the post-etching safety value, the different lengths of the protrusions in the first direction, and the various second spacings between adjacent second entity patterns, a second spacing equal to the post-etching safety value and the length of the protrusions in the first direction corresponding to the second spacing are obtained, and the length of the protrusions in the first direction corresponding to the second spacing is taken as the safety distance.

8. The optical proximity correction method as described in claim 3, characterized in that, The rule that the third distance between the end of the second pattern and the end of the third pattern facing each other in the first direction has a minimum feature size includes the minimum spacing between adjacent patterns supported by the photolithography process.

9. The optical proximity correction method as described in claim 1, characterized in that, The first pattern includes a metal wire pattern; The second graphic includes a metal wire graphic.

10. An optical proximity correction system, characterized in that, include: A module is provided for providing an initial layout, the initial layout including a plurality of first graphics and second graphics located between adjacent first graphics, the first graphics extending along a first direction and arranged in parallel at intervals along a second direction, the second graphics extending along the first direction and arranged in parallel at intervals along the second direction, the first direction being perpendicular to the second direction, the ends of the first graphics protruding beyond the ends of the second graphics, and the ends of the first graphics and the ends of the second graphics having a first distance in the first direction. The first acquisition module is used to acquire a first graphic and a second graphic whose first distance is greater than the safe distance based on the rule that the ends of the first graphic and the ends of the second graphic have a safe distance in the first direction, and to use the acquired first graphic as the graphic to be corrected. An extension module is used to extend the end of the graphic to be corrected one or more times along the first direction to form a corrected graphic, and to take the corrected graphic formed in the last extension process as the final corrected graphic, wherein the second distance between the end of the final corrected graphic and the end of the second graphic in the first direction is less than or equal to the safety distance.

11. The optical proximity correction system as claimed in claim 10, characterized in that, In the initial layout provided by the providing module, a third shape extending along the first direction is further formed on the side of the first shape and the second shape, and the end of the third shape is spaced apart from and directly opposite the end of the second shape; The extension module is based on the rule that the third distance between the end of the second graphic and the end of the third graphic facing each other in the first direction has a minimum feature size, and the third distance between the end of the modified graphic and the end of the third graphic facing each other is greater than or equal to the minimum feature size.

12. The optical proximity correction system as claimed in claim 11, characterized in that, When the third distance is equal to the minimum feature size, the optical proximity correction system further includes: a first comparison unit, used to compare the second distance with the safety distance, and when the second distance is less than or equal to the safety distance, the corrected image is used as the final corrected image; When the second distance is greater than the safe distance, the difference between the second distance and the safe distance is obtained, and the difference is used as a reference value.

13. The optical proximity correction system as claimed in claim 12, characterized in that, The optical proximity correction system further includes: a selection unit, configured to select any value greater than or equal to the reference value as a second fixed value based on the reference value; A retraction unit is used to retract the end of a third graphic that is directly opposite the end of the graphic to be corrected along the first direction, and the retraction dimension of the retraction process is a second fixed value.

14. A photomask, characterized in that, include: A plurality of first patterns and a second pattern located between adjacent first patterns, wherein the first and second patterns are configured by the optical proximity correction method as described in any one of claims 1-9.

15. The photomask as described in claim 14, characterized in that, The first graphic is used to define the metal wire pattern; The second graphic is used to define the metal wire pattern.

16. A device, characterized in that, It includes at least one memory and at least one processor, the memory storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the optical proximity correction method as described in any one of claims 1-9.

17. A storage medium, characterized in that, The storage medium stores one or more computer instructions for implementing the optical proximity correction method as described in any one of claims 1-9.

18. A computer program product, characterized in that, Includes computer instructions, which, when executed by a processor, are used to implement the optical proximity correction method as described in any one of claims 1-9.

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