Optical proximity correction method, electronic equipment and storage medium

Abstract

The invention provides an optical proximity correction method, electronic equipment and a storage medium, and the method comprises the steps: carrying out the initial correction processing of an initial mask layout, obtaining a corrected mask layout, determining a first mask pattern and a second mask pattern, which violate a standard mask rule, in the corrected mask patterns, and determining the rollback distance of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole and the second through hole and the violation information between the first mask pattern and the second mask pattern, and moving the first mask pattern and the second mask pattern based on the rollback distance to obtain a target mask layout. By considering the distance between the mask pattern through hole and the contact hole, the coverage rate and the electrical property of the metal interconnection layer to the contact hole and the through hole are ensured.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an optical proximity correction method, an electronic device, and a storage medium. Background Art

[0002] In semiconductor manufacturing, Optical Proximity Correction (OPC) technology is used to correct mask patterns. Specifically, using the layout target as the initial mask pattern, the mask pattern is adjusted through multiple iterations until the number of iterations or the alignment criteria are met. The mask pattern must meet mask rule checks (MRC). If OPC corrections violate MRC restrictions, the mask pattern will not move as expected, further causing the simulated outline to not align with the target pattern, resulting in wafer defects and impacting electrical properties.

[0003] In existing technologies, the edge placement error (EPE) of mask patterns that violate MRC is usually calculated and dynamically assigned priorities. That is, mask patterns with larger EPEs are given higher priorities. By sacrificing the movement of lower-priority patterns, the final EPEs of the two patterns are kept at a similar level.

[0004] However, in the prior art, the mask pattern may affect the coverage of the metal interconnection layer on the contact hole or the through hole, resulting in an increase in the resistance of the contact hole or the through hole. Summary of the Invention

[0005] The purpose of this application is to provide an optical proximity correction method, electronic device and storage medium to address the deficiencies in the above-mentioned prior art, so as to solve the problems of low metal interconnect layer coverage and low correction efficiency in the prior art.

[0006] To achieve the above objectives, the technical solutions adopted in this application are as follows: In a first aspect, the present application provides an optical proximity correction method, the method comprising: Performing initial correction processing on the initial mask layout to obtain a corrected mask layout, wherein the initial mask layout includes a plurality of initial mask patterns, and the corrected mask layout includes a plurality of corrected mask patterns; determining a first mask pattern and a second mask pattern in the corrected mask pattern that violate standard mask rules, and violation information between the first mask pattern and the second mask pattern, wherein a metal interconnection layer corresponding to the first mask pattern contacts a first contact hole and a first through hole, and a metal interconnection layer corresponding to the second mask pattern contacts a second contact hole and a second through hole; determining a backoff distance of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole; The first mask pattern and the second mask pattern are moved based on the retreat distance to obtain a target mask layout.

[0007] Optionally, the violation information includes: a first violation edge of the first mask pattern, a second violation edge of the second mask pattern, a standard distance and an actual distance between the first violation edge and the second violation edge; The step of determining the setback distances of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole includes: determining a first distance between the first violating edge and a boundary of a first through-hole, a second distance between the first violating edge and a boundary of a first contact hole, a third distance between the second violating edge and a boundary of a second through-hole, and a fourth distance between the second violating edge and a boundary of a second contact hole; The retraction distances of the first mask pattern and the second mask pattern are determined according to the first distance, the second distance, the third distance, the fourth distance, the standard distance, and the actual distance.

[0008] Optionally, determining the retraction distances of the first mask pattern and the second mask pattern according to the first distance, the second distance, the third distance, the fourth distance, the standard distance, and the actual distance includes: Determining a first through-hole value according to the first distance and a preset through-hole weight, and determining a first contact hole value according to the second distance and a preset contact hole weight; Determining a second through-hole value according to the third distance and the through-hole weight, and determining a second contact hole value according to the fourth distance and the contact hole weight; The setback distances of the first mask pattern and the second mask pattern are determined according to the first through-hole value, the first contact hole value, the second through-hole value, the second contact hole value, the standard distance, and the actual distance.

[0009] Optionally, determining the setback distances of the first mask pattern and the second mask pattern according to the first through-hole value, the first contact hole value, the second through-hole value, the second contact hole value, the standard distance, and the actual distance includes: determining a first mask weight and a second mask weight according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value; The backoff distances of the first mask pattern and the second mask pattern are determined according to the first mask weight, the second mask weight, the standard distance, and the actual distance.

[0010] Optionally, determining a first mask weight and a second mask weight according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value includes: taking the sum of the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value as a first intermediate value; taking the sum of the first through hole value and the first contact hole value as a second intermediate value; The sum of the second through hole value and the second contact hole value is used as a third intermediate value; using a quotient of the second intermediate value and the first intermediate value as a first mask weight; The quotient of the third intermediate value and the first intermediate value is used as a second mask weight.

[0011] Optionally, determining the backoff distances of the first mask pattern and the second mask pattern according to the first mask weight, the second mask weight, the standard distance, and the actual distance includes: Taking the difference between the standard distance and the actual distance as the first difference; taking the sum of the first mask weight and the second mask weight as a first sum; taking a quotient of the first mask weight and the first sum as a first quotient, and taking a quotient of the second mask weight and the first sum as a second quotient; multiplying the first difference by the first quotient as the retreat distance of the first mask pattern; The product of the first difference and the second quotient is used as the retreat distance of the second mask pattern.

[0012] Optionally, after moving the first mask pattern and the second mask pattern based on the retraction distance, the method further includes: A safety test is performed on the first mask pattern and the second mask pattern after being moved. If the test fails, the through hole weight and the contact hole weight are adjusted according to the test results, and the first mask pattern and the second mask pattern are moved again based on the adjusted through hole weight and the adjusted contact hole weight.

[0013] Optionally, the performing initial correction processing on the initial mask layout includes: Determining an initial mask rule, wherein the initial mask rule includes: a process limit value of the mask pattern being less than a positive value of a standard process limit value; According to the initial mask rule, the initial mask layout is subjected to multiple initial correction processes.

[0014] In a third aspect, the present application provides an electronic device comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the optical proximity correction method as described above.

[0015] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the optical proximity correction method as described above are executed.

[0016] The beneficial effects of the present application are as follows: first, an initial correction process is performed on the initial mask layout to obtain a corrected mask layout, and then the first mask pattern and the second mask pattern in the corrected mask pattern in the corrected mask layout that violate the standard mask rules, as well as the violation information between the first mask pattern and the second mask pattern, are determined, and based on the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole, the retreat distance of the first mask pattern and the second mask pattern is determined, and the first mask pattern and the second mask pattern are moved based on the retreat distance to obtain the target mask layout. When calculating the retreat distance, the present application takes into account the through holes and contact holes corresponding to the first mask pattern and the second mask pattern, thereby ensuring that mask patterns with higher coverage requirements are given a higher correction priority, and ensuring the coverage and electrical properties of the contact holes and through holes by the metal interconnection layer. In addition, after the mask pattern is retreated, there is no need to perform correction processing again, which greatly reduces the OPC processing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic diagram of a mask pattern after OPC correction in the prior art; Figure 2 is an example flow chart of an optical proximity correction method provided in an embodiment of the present application; Figure 3 is a schematic diagram of a corrected mask pattern provided in an embodiment of the present application; Figure 4This is a schematic diagram of a process for determining the retreat distances of a first mask pattern and a second mask pattern provided by an embodiment of the present application; Figure 5 This is a schematic diagram of a process for determining a first mask weight and a second mask weight provided by this embodiment; Figure 6 This is another flowchart of determining the retreat distances of the first mask pattern and the second mask pattern provided by an embodiment of the present application; Figure 7 is a schematic diagram of the results of an optical proximity correction method provided in an embodiment of the present application; Figure 8 This is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of illustration and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps without logical context can be reversed or implemented simultaneously. In addition, those skilled in the art, under the guidance of the contents of this application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0020] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0021] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0022] Figure 1 This is a schematic diagram of the mask pattern after OPC correction in the prior art. Figure 1The OPC processing in the prior art is introduced. First, the EPE of the mask pattern that violates the MRC is calculated, and the priority of the mask pattern a and the mask pattern b is dynamically assigned according to the EPE, where the mask pattern with a larger EPE has a higher priority, and the mask pattern with a smaller EPE has a lower priority. Then, based on the priority of each mask pattern, a fallback is performed to keep the EPE of the mask pattern a and the mask pattern b at a similar level. Figure 1 In the example, the EPE of mask pattern a is 21 nanometers, and the EPE of mask pattern b is 18 nanometers. The simulated contour of mask pattern b, after back-moving using conventional techniques, does not fully cover the contact holes in the metal interconnect layer, causing changes in the resistance of the contact holes, impacting electrical properties, and potentially causing defects due to diffusion of filler in the contact holes. Furthermore, after the OPC processing of mask patterns a and b, the results of the inspection revealed coverage issues with the contact holes, necessitating another round of OPC correction. This increased processing time and impacted efficiency.

[0023] Based on this, the present application proposes an optical proximity correction method, which first performs an initial correction process on the initial mask layout so that the simulated contour of the corrected mask layout fits the target contour, and then determines the mask patterns that violate the standard mask rules and the violation information between the mask patterns in the multiple corrected mask patterns in the corrected mask layout, and then determines the backoff distance of each mask pattern based on the violation information, through holes and contact holes, and moves the corresponding mask pattern based on the backoff distance. The present application determines the backoff distance of each mask pattern based on the distance between the through holes and the contact holes, thereby ensuring that mask patterns with higher coverage requirements are given a higher correction priority, thereby ensuring the coverage and electrical properties of the metal interconnect layer for the contact holes and through holes. In addition, after the mask pattern is backed off, there is no need to perform correction processing again, which greatly reduces the OPC processing time.

[0024] Next, refer to Figure 2 The specific process of the optical proximity correction method proposed in this application is introduced. Figure 2 1 is a flowchart illustrating an optical proximity correction method provided in an embodiment of the present application. Optionally, the optical proximity correction method can be applied to electronic devices.

[0025] S201 , performing initial correction processing on an initial mask layout to obtain a corrected mask layout, wherein the initial mask layout includes a plurality of initial mask patterns, and the corrected mask layout includes a plurality of corrected mask patterns.

[0026] The initial mask layout can be composed of multiple pre-set initial mask patterns. Each of these initial mask patterns undergoes initial correction processing. During this process, the difference between the projected simulated contour and the target contour can be predicted by calculating factors such as light diffraction and the distance between the mask pattern and the metal interconnect layer. The pattern on the mask is then actively corrected to bring the simulated contour of each mask pattern closer to the target contour until they are aligned. Standard mask specifications are not considered during this process.

[0027] Optionally, during the initial correction process, the number of correction processes may be determined based on a preset total number of iterations. For example, if the total number of iterations is 10, the number of iterations for the initial correction process may be 8.

[0028] The simulation profile is the actual projection profile of the mask pattern on the mask layout on the silicon wafer, and the target profile is the expected projection profile of the mask pattern on the mask layout on the silicon wafer.

[0029] In this embodiment, the mask pattern may be a mask pattern for forming a metal interconnection layer, and may be a mask pattern corresponding to a first metal interconnection layer (M1), wherein the first metal interconnection layer is respectively connected to a contact hole and a via.

[0030] Optionally, if the ratio of the area formed by the simulated contour of the corrected mask pattern to the area formed by the target contour is greater than a preset ratio threshold, then the simulated contour and the target contour are aligned. Alternatively, if the distance between all edges of the simulated contour of the corrected mask pattern and all edges of the target contour is zero, then the simulated contour and the target contour are aligned.

[0031] S202. Determine the first mask pattern and the second mask pattern in the corrected mask pattern that violate the standard mask rule, as well as violation information between the first mask pattern and the second mask pattern, wherein the metal interconnection layer corresponding to the first mask pattern is in contact with the first contact hole and the first through hole, and the metal interconnection layer corresponding to the second mask pattern is in contact with the second contact hole and the second through hole.

[0032] Optionally, the standard mask rules are process restriction rules that must be followed during mask production, and may include multiple standard process restriction values, such as, for example, a minimum width of 60 nanometers, a minimum pitch of 60 nanometers, a minimum distance between inner corners of 60 nanometers, and a minimum distance between outer corners of 60 nanometers.

[0033] Optionally, multiple corrected mask patterns are subjected to a rule check. If any corrected mask pattern violates the standard mask rules, the corresponding mask pattern violating the rules is used as the first mask pattern and the second mask pattern. Those skilled in the art will appreciate that the minimum spacing, the minimum distance between inner corners, and the minimum distance between outer corners are all distances between two mask patterns. Therefore, the mask patterns violating the rules typically exist in the form of a mask pattern group, that is, the mask patterns violating the rules may include the first mask pattern and the second mask pattern.

[0034] For example, if the corrected mask pattern x and the corrected mask pattern y violate the standard mask rules, the corrected mask pattern x can be used as the first mask pattern, and the corrected mask pattern y can be used as the second mask pattern. It is worth noting that in the corrected mask layout, there can be multiple first mask patterns and multiple second mask patterns. In the subsequent correction process, the first mask patterns and second mask patterns that violate the standard mask rules can be grouped together, and the violation information between the first mask patterns and the second mask patterns in each group can be determined.

[0035] The violation information may include each violation edge in the first mask pattern and the second mask pattern, the distance between each violation edge, and the standard distance specified by the standard mask rule. The first mask pattern may include one violation edge, and the second mask pattern may also include one violation edge.

[0036] Alternatively, the metal interconnect layer corresponding to the first mask pattern may contact multiple contact holes and multiple through-holes, with the contact hole closest to the edge of the first mask pattern involved in the violation being used as the first contact hole, and the through-hole closest to the edge of the first mask pattern involved in the violation being used as the first through-hole. The metal interconnect layer corresponding to the second mask pattern may contact multiple contact holes and multiple through-holes, with the contact hole closest to the edge of the second mask pattern involved in the violation being used as the second contact hole, and the through-hole closest to the edge of the second mask pattern involved in the violation being used as the second through-hole.

[0037] S203 , determining the backoff distances of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole.

[0038] Optionally, since the first mask pattern and the second mask pattern violate the standard mask rules after the initial correction processing in step S201, the first mask pattern and the second mask pattern need to be rolled back so that the rolled-back first mask pattern and the second mask pattern comply with the standard mask rules.

[0039] As an optional embodiment, the first mask weight corresponding to the first mask pattern and the second mask weight corresponding to the second mask pattern can be determined based on the first through hole, the second through hole, the first contact hole and the second contact hole, and then the backoff distances of the first mask pattern and the second mask pattern can be determined based on the violation information, the first mask weight and the second mask weight.

[0040] S204 , moving the first mask pattern and the second mask pattern based on the back-off distance to obtain a target mask layout.

[0041] Specifically, the first mask pattern is moved based on the backoff distance of the first mask pattern, and the second mask pattern is moved based on the backoff distance of the second mask pattern, so that the actual distance between the edge of the first mask pattern involving the violation and the edge of the second mask pattern involving the violation is equal to the specification distance in the standard mask rule, so that the first mask pattern and the second mask pattern after backoff comply with the standard mask rule.

[0042] It is worth noting that the backward movement refers to movement in a direction that complies with standard mask rules. For example, Figure 3 Schematic diagram of a corrected mask pattern provided in an embodiment of the present application. Figure 3 As shown, the spacing between the corrected mask pattern Q and the corrected mask pattern P is 30 nanometers. If the corrected mask pattern P is to the left of the corrected mask pattern Q, and the distance between the first illegal edge of the corrected mask pattern P and the second illegal edge of the corrected mask pattern Q is less than the standard process limit value in the standard mask rule, then the back-off movement of the corrected mask pattern P is to the left, and the back-off movement of the corrected mask pattern Q is to the right.

[0043] In this embodiment, an initial correction process is first performed on the initial mask layout to obtain a corrected mask layout. The first and second mask patterns in the corrected mask pattern in the corrected mask layout that violate standard mask rules are then determined, as well as the violation information between the first and second mask patterns. Based on the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole, the setback distance of the first and second mask patterns is determined. The first and second mask patterns are then moved based on the setback distance to obtain a target mask layout. This embodiment takes into account the through holes and contact holes corresponding to the first and second mask patterns when calculating the setback distance, thereby ensuring that mask patterns with higher coverage requirements are given a higher correction priority, thereby ensuring the coverage and electrical properties of the contact holes and through holes by the metal interconnect layer. Furthermore, after the mask pattern is set back, no further correction process is required, significantly reducing OPC processing time.

[0044] As an optional implementation manner, the violation information may include: a first violation edge of the first mask pattern, a second violation edge of the second mask pattern, a standard distance between the first violation edge and the second violation edge, and an actual distance.

[0045] The illegal edge is an edge in the corrected mask pattern that violates the standard mask rule, the standard distance is the distance specified in the standard mask rule, and the actual distance is the distance between the first illegal edge and the second illegal edge.

[0046] In this embodiment, the first violating edge is the edge of the first mask pattern that is closest to the second mask pattern, and the second violating edge is the edge of the second mask pattern that is closest to the first mask pattern.

[0047] For example, Figure 3 As shown, the spacing between the corrected mask pattern Q and the corrected mask pattern P is 30 nanometers, the standard distance is 60 nanometers, and the actual distance between the violating edges is 30 nanometers.

[0048] Based on this, the specific implementation method of determining the backoff distances of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole in the above step S203 is as follows.

[0049] Optionally, a first distance between the first violating edge and the boundary of the first through hole, a second distance between the first violating edge and the boundary of the first contact hole, a third distance between the second violating edge and the boundary of the second through hole, and a fourth distance between the second violating edge and the boundary of the second contact hole are determined.

[0050] In this embodiment, the boundary of each through hole and contact hole refers to the boundary between the through hole or the contact hole and the illegal edge of the corresponding mask pattern.

[0051] For example, Figure 3 As shown, the distance between the first violating edge of the corrected mask pattern Q and the boundary of the first through hole is a first distance a1, the distance between the first violating edge and the boundary of the first contact hole is a second distance b1, the distance between the second violating edge of the corrected mask pattern P and the boundary of the through hole is a third distance a2, and the distance between the second violating edge and the boundary of the contact hole is a fourth distance b2.

[0052] Optionally, the first distance, the second distance, the third distance, and the fourth distance may be determined by simulation software.

[0053] Optionally, the retreat distances of the first mask pattern and the second mask pattern are determined according to the first distance, the second distance, the third distance, the fourth distance, the standard distance, and the actual distance.

[0054] As an optional implementation, the first mask weight corresponding to the first mask pattern and the second mask weight corresponding to the second mask pattern can be determined based on the first distance, the second distance, the third distance and the fourth distance, and then the backoff distances of the first mask pattern and the second mask pattern can be determined based on the violation information, the first mask weight and the second mask weight.

[0055] In this embodiment, the first distance, the second distance, the third distance and the fourth distance are first determined, and then based on the first distance, the second distance, the third distance, the fourth distance, the standard distance and the actual distance, it is ensured that the simulation contour corresponding to the mask pattern obtained by moving the back-off distance can cover the through holes and contact holes to the greatest extent.

[0056] Next, refer to Figure 4 The specific method for determining the retreat distance of the first mask pattern and the second mask pattern in the above steps is introduced. Figure 4 This is a flow chart of determining the retreat distances of a first mask pattern and a second mask pattern provided in an embodiment of the present application.

[0057] S401 : Determine a first through-hole value according to a first distance and a preset through-hole weight, and determine a first contact hole value according to a second distance and a preset contact hole weight.

[0058] As an optional implementation, the through hole weight and the contact hole weight are preset values.

[0059] As another optional embodiment, the through-hole weight and the contact hole weight can be determined according to the material of the metal interconnection layer. Specifically, the through-hole and the contact hole are actually in the shape of a quadrangular pyramid. If the metal interconnection layer is made of copper, the cross-section of the metal interconnection layer is an inverted trapezoid that is wide at the top and narrow at the bottom. The contact hole is located below the metal interconnection layer, and the morphology is wide at the top and narrow at the bottom. At this time, the larger surface of the contact hole is in contact with the smaller surface of the metal interconnection layer, and there is a greater risk that the metal interconnection layer cannot cover the contact hole, which will affect the resistance and the leakage of the contact hole material. The through-hole is located above the metal interconnection layer, and the morphology is wide at the top and narrow at the bottom. At this time, the smaller surface of the through-hole is connected to the larger surface of the metal interconnection layer, and it is not easy for the metal interconnection layer to not cover the through-hole. Therefore, the contact hole weight can be greater than the through-hole weight. Exemplarily, the contact hole weight can be 1, and the through-hole weight can be 0.8.

[0060] If the metal interconnect layer is made of aluminum, its cross-section is an inverted trapezoid, narrow at the top and wide at the bottom. The contact hole is located below the metal interconnect layer, and the through hole is located above the metal interconnect layer. In this case, the smaller surface of the through hole contacts the smaller surface of the metal interconnect layer, and the coverage problem is relatively balanced. In this case, the contact hole weight can be the same as the through hole weight. For example, the contact hole weight and the through hole weight can both be 1.

[0061] Optionally, the first through-hole value represents the importance value of the through-hole corresponding to the first mask pattern. The first contact hole value represents the importance value of the first mask pattern to the corresponding contact hole.

[0062] S402 : Determine a second through-hole value according to the third distance and the through-hole weight, and determine a second contact hole value according to the fourth distance and the contact hole weight.

[0063] Optionally, the second through-hole value represents the importance value of the through-hole corresponding to the second mask pattern. The second contact hole value represents the importance value of the second mask pattern to the corresponding contact hole.

[0064] S403 , determining the retreat distances of the first mask pattern and the second mask pattern according to the first through-hole value, the first contact hole value, the second through-hole value, the second contact hole value, the standard distance, and the actual distance.

[0065] As an optional implementation, the first mask weight and the second mask weight are determined respectively according to the first through-hole value, the first contact hole value, the second through-hole value and the second contact hole value, and then the setback distances of the first mask pattern and the second mask pattern are determined according to the first mask weight, the second mask weight, the standard distance and the actual distance.

[0066] In this embodiment, the first through-hole value, the first contact hole value, the second through-hole value and the second contact hole value are determined respectively according to the through-hole weight and the contact hole weight, so as to ensure that the simulated contour of the mask pattern obtained by moving the back-off distance can cover the through-hole and the contact hole to the greatest extent.

[0067] As an optional implementation, in the above step S401, the specific method for determining the first through-hole value according to the first distance and the preset through-hole weight is: taking the product of the first distance and the through-hole weight as the first through-hole value.

[0068] Optionally, a specific method for determining the first contact hole value according to the second distance and a preset contact hole weight is: taking the product of the second distance and the contact hole weight as the first contact hole value.

[0069] Optionally, a specific method for determining the second through-hole value according to the third distance and a preset through-hole weight is: taking the product of the third distance and the through-hole weight as the second through-hole value.

[0070] Optionally, a specific method for determining the second contact hole value according to the fourth distance and a preset contact hole weight is: taking the product of the fourth distance and the contact hole weight as the second contact hole value.

[0071] In this embodiment, the product of the first distance and the through-hole weight is used as the first through-hole value, so as to quantify the process risk into a mathematical indicator, thereby improving the chip yield.

[0072] Next, the method for determining the retreat distances of the first mask pattern and the second mask pattern in the above step S403 is introduced.

[0073] Optionally, a first mask weight and a second mask weight are determined according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value.

[0074] Specifically, a first mask weight corresponding to the first mask pattern and a second mask weight corresponding to the second mask pattern are determined according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value.

[0075] Specifically, the first through-hole value and the first contact hole value are used as a ratio of the sum of all through-hole values ​​and all contact hole values ​​as the first mask weight. The second through-hole value and the second contact hole value are used as a ratio of the sum of all through-hole values ​​and all contact hole values ​​as the second mask weight. Here, all through-hole values ​​may be through-hole values ​​corresponding to each mask pattern in the current violation group, and all contact hole values ​​may be contact hole values ​​corresponding to each mask pattern in the current violation group.

[0076] Optionally, the backoff distances of the first mask pattern and the second mask pattern are determined according to the first mask weight, the second mask weight, the standard distance, and the actual distance.

[0077] As an optional implementation, the backoff distances of the first mask pattern and the second mask pattern may be determined respectively based on the difference between the standard distance and the actual distance, and then based on the difference and the first mask weight and the second mask weight.

[0078] In this embodiment, the first mask weight and the second mask weight are determined based on the first through hole value, the first contact hole value, the second through hole value and the second contact hole value, and the retreat distances of the first mask pattern and the second mask pattern are determined based on the first mask weight, the second mask weight, the standard distance and the actual distance. Therefore, the priority of the mask pattern retreat is determined according to the through hole position and contact hole position corresponding to each mask pattern, thereby improving the coverage of the through hole and the contact hole.

[0079] As an optional implementation, Figure 5 FIG. 1 is a flow chart of determining the first mask weight and the second mask weight provided by this embodiment. Figure 5 As shown, the specific steps of determining the first mask weight and the second mask weight in the above steps are as follows.

[0080] S501 , taking the sum of the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value as a first intermediate value.

[0081] S502 , taking the sum of the first through-hole value and the first contact hole value as a second intermediate value.

[0082] S503 , taking the sum of the second through hole value and the second contact hole value as a third intermediate value.

[0083] S504 : Taking the quotient of the second intermediate value and the first intermediate value as the first mask weight.

[0084] Alternatively, the first mask weight can be obtained by the following formula (1): (1) Where W1 is the first mask weight, a1 is the first distance, n1 is the through-hole weight, is the first through hole value, b1 is the second distance, n2 is the contact hole weight, is the first contact hole value, is the second intermediate value, a2 is the third distance, b2 is the fourth distance, is the first intermediate value.

[0085] S505 : Taking the quotient of the third intermediate value and the first intermediate value as the second mask weight.

[0086] Optionally, the second mask weight can be obtained by the following formula (2): (1) Among them, W2 is the second mask weight, a2 is the third distance, b2 is the fourth distance, is the second through-hole value, is the second contact hole value, The third intermediate value.

[0087] In this embodiment, the priority of mask pattern retreat is determined by the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value, thereby further improving the coverage of the through-hole and the contact hole.

[0088] Next, refer to Figure 6 The specific steps of determining the retreat distances of the first mask pattern and the second mask pattern according to the first mask weight, the second mask weight, the standard distance and the actual distance in the above steps are introduced. Figure 6 This is another flowchart for determining the retreat distances of the first mask pattern and the second mask pattern provided in an embodiment of the present application.

[0089] S601: The difference between the standard distance and the actual distance is taken as the first difference.

[0090] S602: Taking the sum of the first mask weight and the second mask weight as a first sum.

[0091] S603 : Taking the quotient of the first mask weight and the first sum as the first quotient, and taking the quotient of the second mask weight and the first sum as the second quotient.

[0092] S604: Taking the product of the first difference and the first quotient as the retreat distance of the first mask pattern.

[0093] Alternatively, the setback distance of the first mask pattern can be obtained by the following formula (3): (3) Where S1 is the backoff distance of the first mask pattern, H is the standard distance, s is the actual distance, W1 is the first mask weight, and W2 is the second mask weight.

[0094] S605 : Taking the product of the first difference and the second quotient as the retreat distance of the second mask pattern.

[0095] Alternatively, the setback distance of the second mask pattern can be obtained by the following formula (4): (4) Wherein, S2 is the retreat distance of the second mask pattern.

[0096] In this embodiment, the setback distances of the first mask pattern and the second mask pattern are determined by the first mask weight, the second mask weight, the standard distance, and the actual distance, thereby improving the coverage of the through hole and the contact hole.

[0097] As an optional embodiment, after moving the first mask pattern and the second mask pattern based on the back-off distance, the following steps can also be performed: performing a safety test on the moved first mask pattern and the second mask pattern; if the test fails, adjusting the through-hole weight and the contact hole weight according to the test results, and moving the first mask pattern and the second mask pattern again based on the adjusted through-hole weight and the adjusted contact hole weight.

[0098] Optionally, safety testing can include spacing compliance testing, via and contact hole coverage testing, and contact-free testing. If the test fails, it means that the mask pattern still has violations, and the via and contact hole weights can be adjusted based on the test results.

[0099] Specifically, if the via coverage is insufficient, the via weight is increased; if the contact hole spacing is insufficient, the contact hole weight is increased, thereby re-moving the offending mask pattern based on the new weight.

[0100] It is worth noting that in this embodiment, all illegal mask patterns can be subjected to security tests and adjusted according to the test results, rather than being limited to the first mask pattern and the second mask pattern, so that the target mask layout complies with the standard mask rules, and the simulation contours corresponding to each mask pattern cover the through holes and contact holes to the greatest extent.

[0101] In this embodiment, a safety test is performed on the moved first mask pattern and the second mask pattern. If the test fails, the through-hole weight and the contact hole weight are adjusted according to the test results, and the first mask pattern and the second mask pattern are moved again based on the adjusted through-hole weight and the adjusted contact hole weight, thereby improving the test pass rate and reducing the defect risk.

[0102] As mentioned above, the mask pattern rollback is performed on the first mask pattern and the second mask pattern that violate the standard mask rule in the corrected mask layout after the initial correction process.

[0103] In one embodiment, the specific steps of performing initial correction processing on the initial mask layout may include: determining an initial mask rule; and performing multiple initial correction processing on the initial mask layout according to the initial mask rule.

[0104] In this embodiment, the initial mask rule may include: a process limit value of the mask pattern is smaller than a positive value of a standard process limit value.

[0105] In this embodiment, the initial mask rule is used to restrict the movement of each mask pattern when multiple correction processes are performed on multiple initial mask patterns in the initial mask layout, specifically, to restrict contact between the initial mask patterns.

[0106] Optionally, the standard mask rules may include standard process limits, and the process limits in the initial mask rules may correspond one-to-one with the standard process limits. For example, the distance between two mask patterns corresponds to a standard process limit of 60 nanometers, while the corresponding process limit in the initial mask rules is 10 nanometers.

[0107] In one embodiment, the initial mask layout is subjected to multiple initial correction processes according to the initial mask rule. The correction processes may be performed on multiple initial mask patterns respectively according to the initial mask rule, so as to avoid the initial mask patterns from contacting and connecting with each other.

[0108] In this embodiment, an initial mask rule is determined, and the initial mask layout is corrected multiple times according to the initial mask rule, thereby preventing mask patterns from contacting and connecting with each other, which would cause increased physical wear and defects to be transferred to the wafer.

[0109] As an optional implementation, Figure 7This is a schematic diagram of the results of an optical proximity correction method provided in an embodiment of the present application. Figure 1 After multiple OPC corrections of the initial mask pattern in the image, it is determined that the mask pattern a and the mask pattern b violate the standard mask rule, so the mask pattern a and the mask pattern b are moved back to obtain Figure 7 The results shown. Figure 7 As shown, the distance between the mask pattern H and the mask pattern G after the back movement is 60 nanometers. At this time, the EPE of the mask pattern a is 33.32 nanometers, and the EPE of the mask pattern b is 20.28 nanometers. Figure 1 The EPE of mask pattern a is 21 nanometers, and the EPE of mask pattern b is 18 nanometers. The EPE is not uniform, but Figure 7 The coverage of the metal interconnect layer of the middle mask pattern b on the contact holes and through holes is greater than Figure 1 The coverage of the metal interconnection layer of the middle mask pattern b on the contact holes and through holes. It can be seen that the present application improves the coverage of the metal interconnection layer on the contact holes and through holes, ensuring the electrical resistance of the contact holes and through holes.

[0110] The present application also provides an electronic device, such as Figure 8 FIG. 8 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, which may include: a processor 801, a memory 802, and a bus. The memory 802 stores machine-readable instructions executable by the processor 801. When the computer device is running, the processor 801 communicates with the memory 802 via the bus. When the machine-readable instructions are executed by the processor 801, the processing of the optical proximity correction method described above is performed.

[0111] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned optical proximity correction method are executed.

[0112] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0113] In addition, the functional units in the various embodiments of the present application can be integrated into a single processing unit, each unit can exist physically separately, or two or more units can be integrated into a single unit. If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0114] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

Claims

1. An optical proximity correction method, characterized in that: The method comprises: Performing initial correction processing on the initial mask layout to obtain a corrected mask layout, wherein the initial mask layout includes a plurality of initial mask patterns, and the corrected mask layout includes a plurality of corrected mask patterns; determining a first mask pattern and a second mask pattern in the corrected mask pattern that violate standard mask rules, and violation information between the first mask pattern and the second mask pattern, wherein a metal interconnection layer corresponding to the first mask pattern contacts a first contact hole and a first through hole, and a metal interconnection layer corresponding to the second mask pattern contacts a second contact hole and a second through hole; determining a backoff distance of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole; The first mask pattern and the second mask pattern are moved based on the retreat distance to obtain a target mask layout.

2. The optical proximity correction method according to claim 1, wherein: The violation information includes: a first violation edge of the first mask pattern, a second violation edge of the second mask pattern, a standard distance between the first violation edge and the second violation edge, and an actual distance; The step of determining the setback distances of the first mask pattern and the second mask pattern according to the violation information, the first contact hole, the first through hole, the second contact hole, and the second through hole includes: determining a first distance between the first violating edge and a boundary of a first through-hole, a second distance between the first violating edge and a boundary of a first contact hole, a third distance between the second violating edge and a boundary of a second through-hole, and a fourth distance between the second violating edge and a boundary of a second contact hole; The retraction distances of the first mask pattern and the second mask pattern are determined according to the first distance, the second distance, the third distance, the fourth distance, the standard distance, and the actual distance.

3. The optical proximity correction method according to claim 2, wherein: The determining the retreat distances of the first mask pattern and the second mask pattern according to the first distance, the second distance, the third distance, the fourth distance, the standard distance, and the actual distance includes: Determining a first through-hole value according to the first distance and a preset through-hole weight, and determining a first contact hole value according to the second distance and a preset contact hole weight; Determining a second through-hole value according to the third distance and the through-hole weight, and determining a second contact hole value according to the fourth distance and the contact hole weight; The setback distances of the first mask pattern and the second mask pattern are determined according to the first through-hole value, the first contact hole value, the second through-hole value, the second contact hole value, the standard distance, and the actual distance.

4. The optical proximity correction method according to claim 3, wherein: The determining the setback distances of the first mask pattern and the second mask pattern according to the first through-hole value, the first contact hole value, the second through-hole value, the second contact hole value, the standard distance, and the actual distance includes: determining a first mask weight and a second mask weight according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value; The backoff distances of the first mask pattern and the second mask pattern are determined according to the first mask weight, the second mask weight, the standard distance, and the actual distance.

5. The optical proximity correction method according to claim 4, wherein: The determining a first mask weight and a second mask weight according to the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value includes: taking the sum of the first through-hole value, the first contact hole value, the second through-hole value, and the second contact hole value as a first intermediate value; taking the sum of the first through hole value and the first contact hole value as a second intermediate value; The sum of the second through hole value and the second contact hole value is used as a third intermediate value; using a quotient of the second intermediate value and the first intermediate value as a first mask weight; The quotient of the third intermediate value and the first intermediate value is used as a second mask weight.

6. The optical proximity correction method according to claim 4, wherein: The determining the retreat distances of the first mask pattern and the second mask pattern according to the first mask weight, the second mask weight, the standard distance, and the actual distance includes: Taking the difference between the standard distance and the actual distance as the first difference; taking the sum of the first mask weight and the second mask weight as a first sum; taking a quotient of the first mask weight and the first sum as a first quotient, and taking a quotient of the second mask weight and the first sum as a second quotient; multiplying the first difference by the first quotient as the retreat distance of the first mask pattern; The product of the first difference and the second quotient is used as the retreat distance of the second mask pattern.

7. The optical proximity correction method according to claim 3, wherein: After moving the first mask pattern and the second mask pattern based on the retreat distance, the method further includes: A safety test is performed on the first mask pattern and the second mask pattern after being moved. If the test fails, the through hole weight and the contact hole weight are adjusted according to the test results, and the first mask pattern and the second mask pattern are moved again based on the adjusted through hole weight and the adjusted contact hole weight.

8. The optical proximity correction method according to claim 1, wherein: The initial correction process for the initial mask layout includes: Determining an initial mask rule, wherein the initial mask rule includes: a process limit value of the mask pattern being less than a positive value of a standard process limit value; According to the initial mask rule, the initial mask layout is subjected to multiple initial correction processes.

9. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor executes the machine-readable instructions to perform the steps of the optical proximity correction method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of the optical proximity correction method according to any one of claims 1 to 8.

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