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

Abstract

The invention discloses an optical proximity correction method and system, a mask and equipment, a storage medium and a computer program, and the method comprises the steps: carrying out the global optical proximity correction processing of a plurality of original patterns, and forming a plurality of initial correction patterns and a plurality of first simulation patterns corresponding to the plurality of initial correction patterns; obtaining a first simulation graph of which the edge placement error does not meet the correction standard and an initial correction graph corresponding to the first simulation graph, and taking the initial correction graph as a to-be-corrected graph; carrying out multiple times of local optical proximity correction, namely carrying out local optical proximity correction processing on the to-be-corrected graph to form an initially corrected graph and a second simulation graph corresponding to the initially corrected graph; and acquiring a second simulation graph of which the edge placement error does not meet the correction standard and an initially corrected graph corresponding to the second simulation graph, and taking the initially corrected graph as a graph to be corrected in the next local optical proximity correction. And the efficiency of the optical proximity correction method is improved.

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 and apparatus, a storage medium, and a computer program. Background Technology

[0002] To transfer a pattern from a photomask to the surface of a silicon wafer, the process typically involves an exposure step, a development step following the exposure step, and an etching step following the development step. In the exposure step, light passes through the light-transmitting areas of the photomask and shines onto the silicon wafer coated with photoresist, causing a chemical reaction in the photoresist. In the development step, the different solubility of the developer in the photoresist and the unphotoresisted photoresist creates a photolithographic pattern, transferring the pattern from the photomask to the photoresist. In the etching step, the silicon wafer is etched based on the photolithographic pattern formed by the photoresist layer, further transferring the pattern from the photomask onto the silicon wafer.

[0003] However, as device dimensions shrink, the difference between the pattern on the chip surface and the original photomask pattern increases after photolithography. To avoid inconsistencies between the chip pattern and the mask pattern caused by optical proximity effect, the current solution is usually to perform optical proximity correction (OPC) on the mask pattern, and then transfer the pattern based on the corrected mask pattern. The OPC correction process typically requires a mask manufacturing rule check to ensure final pattern convergence and mask fabrication accuracy. 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 mask and device, a storage medium, and a computer program, which is beneficial to further improve the efficiency of the optical proximity correction method.

[0005] To address the aforementioned problems, this invention provides an optical proximity correction method, comprising: providing an initial image layer, the initial image layer including multiple original graphics; performing global optical proximity correction processing on the multiple original graphics to form multiple initial corrected graphics and multiple first simulated graphics corresponding to the multiple initial corrected graphics; acquiring the first simulated graphics whose edge placement error does not meet the correction standard, and the initial corrected graphics corresponding to them, and using the initial corrected graphics as graphics to be corrected; performing multiple local optical proximity correction steps, the local optical proximity correction steps including: performing local optical proximity correction processing on the graphics to be corrected to form an initial corrected graphic, and a second simulated graphic corresponding to the initial corrected graphic; determining whether the edge placement error of the second simulated graphic meets the correction standard; when the edge placement error of the second simulated graphic does not meet the correction standard, acquiring the second simulated graphic whose edge placement error does not meet the correction standard, and the initial corrected graphic corresponding to it, and using the initial corrected graphic as the graphics to be corrected in the next local optical proximity correction; when the edge placement error of the second simulated graphic meets the correction standard, using the initial corrected graphic as a photomask graphic.

[0006] Optionally, the step of performing global optical proximity correction processing on multiple original graphics includes: dividing the edges corresponding to the contours of the original graphics into multiple first line segments, each first line segment including two endpoints and a first sampling point located between the two endpoints; and using the multiple first line segments to perform global optical proximity correction processing on the original graphics until the absolute value of the edge placement error at the first sampling point is within a first threshold range.

[0007] Optionally, in the step of dividing the edge corresponding to the outline of the original graphic into multiple first line segments, the first sampling point is located at the center of the first line segment.

[0008] Optionally, the step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard includes: obtaining the edge placement error of the first simulated graphic at each endpoint position that does not meet the first preset condition, wherein the first preset condition is δ1×δ2<0, δ1 is the edge placement error of the first simulated graphic at any endpoint of the first line segment, and δ2 is the edge placement error of the first simulated graphic at the other endpoint of the first line segment.

[0009] Optionally, before the step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard, and the corresponding initial corrected graphic, the method further includes: determining whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

[0010] Optionally, after performing multiple local optical proximity correction steps, the optical proximity correction method further includes adding an auxiliary pattern around the photomask pattern.

[0011] Optionally, in the step of adding an auxiliary pattern around the photomask pattern, the auxiliary pattern is a scattering bar, and the linewidth of the auxiliary pattern is greater than or equal to the minimum linewidth of the mask writing rule, and less than or equal to the resolution of the photolithography process.

[0012] Accordingly, embodiments of the present invention also provide an optical proximity correction system, comprising: a providing module for providing an initial image layer, the initial image layer including multiple original images; a global optical proximity correction processing module for performing global optical proximity correction processing on the multiple original images to form multiple initial corrected images, and multiple first simulated images corresponding to the multiple initial corrected images; an acquisition module for acquiring the first simulated images whose edge placement errors do not meet the correction criteria, and the corresponding initial corrected images, and using the initial corrected images as images to be corrected; and a local optical proximity correction module for performing multiple local optical proximity correction steps, the local optical proximity correction steps including: performing local optical proximity correction processing on the images to be corrected to form an initial corrected image, and a second simulated image corresponding to the initial corrected image; determining whether the edge placement error of the second simulated image meets the correction criteria; when the edge placement error of the second simulated image does not meet the correction criteria, acquiring the second simulated image whose edge placement error does not meet the correction criteria, and the corresponding initial corrected image, and using the initial corrected image as the image to be corrected in the next local optical proximity correction; when the edge placement error of the second simulated image meets the correction criteria, using the initial corrected image as a photomask image.

[0013] Optionally, the optical proximity correction system further includes a judgment module for judging whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

[0014] Optionally, the optical proximity correction system further includes an addition module for adding auxiliary patterns around the photomask pattern.

[0015] Accordingly, embodiments of the present invention also provide a photomask, including a pattern obtained using the optical proximity correction method provided in embodiments of the present invention.

[0016] 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, wherein the one or more computer instructions are executed by the processor to implement the optical proximity correction method provided in embodiments of the present invention.

[0017] 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 embodiments of the present invention.

[0018] 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.

[0019] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0020] This invention provides an optical proximity correction method. It involves performing global optical proximity correction processing on multiple original images to form multiple initial corrected images and multiple first simulated images corresponding to the initial corrected images. The method then acquires the first simulated image whose edge placement error does not meet the correction standard, along with its corresponding initial corrected image, and uses this initial corrected image as the image to be corrected. Multiple local optical proximity correction steps are then performed. Each local optical proximity correction step includes: performing local optical proximity correction processing on the image to be corrected to form an initial corrected image and a second simulated image corresponding to the initial corrected image; determining whether the edge placement error of the second simulated image meets the correction standard; when the edge placement error of the second simulated image does not meet the correction standard, acquiring the second simulated image whose edge placement error does not meet the correction standard, along with its corresponding initial corrected image, and using this initial corrected image as the image to be corrected in the next local optical proximity correction; when the edge placement error of the second simulated image meets the correction standard, using the initial corrected image as the photomask image. Compared to existing methods that perform multiple global optical proximity corrections on all original images to form a photomask pattern, this invention first performs a global optical proximity correction process on the original images to form multiple initial corrected images and multiple first simulated images corresponding to the initial corrected images. Then, it obtains the first simulated image whose edge placement error does not meet the correction standard, and its corresponding initial corrected image, and uses the initial corrected image as the image to be corrected. Next, it performs multiple local optical proximity correction processes. Each local optical proximity correction process involves a second simulated image that does not meet the correction standard, and its corresponding initial corrected image. That is, after each local optical proximity correction process, it is determined whether the edge placement error of the second simulated image meets the correction standard. If it does, the initial corrected image of that part is directly used as the photomask pattern and does not enter the next local optical proximity correction process. This continuously reduces the number of images to be corrected in the local optical proximity correction process, thereby reducing the running time of the optical proximity correction method and improving its efficiency. Attached Figure Description

[0021] Figure 1 This is a flowchart of an embodiment of the optical proximity correction method of the present invention;

[0022] Figures 2 to 5 This is a schematic diagram of the structure corresponding to each step in one embodiment of the optical proximity correction method of the present invention;

[0023] Figure 6 This is a functional block diagram of an embodiment of the optical proximity correction system of the present invention;

[0024] Figure 7 This is a hardware structure diagram of an embodiment of the device provided by the present invention. Detailed Implementation

[0025] Currently, the efficiency of optical proximity correction methods still needs to be improved.

[0026] To address the technical problem, this invention provides an optical proximity correction method.

[0027] refer to Figure 1 The flowchart of an embodiment of the optical proximity correction method of the present invention is shown.

[0028] In this embodiment, the optical proximity correction method includes the following basic steps:

[0029] Step S1: Provide an initial version layer, which includes multiple original graphics;

[0030] Step S2: Perform global optical proximity correction processing on the multiple original images to form multiple initial corrected images and multiple first simulated images corresponding to the multiple initial corrected images;

[0031] Step S3: Obtain the first simulated image whose edge placement error does not meet the correction standard, and the corresponding initial correction image, and use the initial correction image as the image to be corrected;

[0032] Step S4: Perform multiple local optical proximity correction steps, the local optical proximity correction steps including:

[0033] Step S41: Perform local optical proximity correction processing on the image to be corrected to form an initial corrected image and a second simulated image corresponding to the initial corrected image;

[0034] Step S42: Determine whether the edge placement error of the second simulated graphic meets the correction standard;

[0035] Step S43: When the edge placement error of the second simulated image does not meet the correction standard, obtain the second simulated image whose edge placement error does not meet the correction standard, and the corresponding initial corrected image, and use the initial corrected image as the image to be corrected in the next local optical proximity correction.

[0036] Step S44: When the edge placement error of the second simulated graphic meets the correction standard, the initial corrected graphic is used as the photomask graphic.

[0037] In this embodiment of the invention, the original image is first subjected to a global optical proximity correction process to form multiple initial corrected images and multiple first simulated images corresponding to the multiple initial corrected images. Then, the first simulated image whose edge placement error does not meet the correction standard is obtained, along with its corresponding initial corrected image, and the initial corrected image is used as the image to be corrected. Next, multiple local optical proximity correction processes are performed. Each local optical proximity correction process is a second simulated image that does not meet the correction standard, along with its corresponding initial corrected image. That is, after each local optical proximity correction process, it is determined whether the edge placement error of the second simulated image meets the correction standard. If it does meet the correction standard, the initial corrected image of that part is directly used as the mask image and does not enter the next local optical proximity correction process. Compared with the existing scheme of performing multiple global optical proximity corrections on all original images to form mask images, this embodiment of the invention can continuously reduce the number of images to be corrected in the local optical proximity correction process, thereby reducing the running time of the optical proximity correction method and improving the efficiency of the optical proximity correction method.

[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 5 This is a schematic diagram of the structure corresponding to 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 version layer 100A, which includes multiple original graphics 100.

[0041] The original pattern 100 refers to the design pattern, which is used as a reference for the edge placement error of the exposure pattern obtained by photolithography simulation.

[0042] After optical proximity correction is performed on the original pattern 100, the resulting pattern is used to create a photomask, which is then used for photolithography to form the corresponding photomask pattern on the wafer.

[0043] refer to Figure 3 Step S2: Perform global optical proximity correction processing on the multiple original patterns 100 to form multiple initial corrected patterns 101, and multiple first simulated patterns (not shown) corresponding to the multiple initial corrected patterns 101.

[0044] Specifically, a global optical proximity correction process is performed on multiple original patterns 100 so that each original pattern 100 can be corrected and compensated, thereby reducing the edge placement error of multiple initial corrected patterns 101 and significantly improving the optical proximity effect.

[0045] It should be noted that by performing global optical proximity correction processing on multiple original graphics 100, it is beneficial to subsequently obtain the first simulated graphics whose edge placement error does not meet the correction standard, as well as the corresponding initial corrected graphics 101. Thus, in the subsequent local optical proximity correction processing, only the initial corrected graphics 101 corresponding to the first simulated graphics that does not meet the correction standard are corrected, reducing the number of graphics processing in the optical proximity correction processing and improving the operating efficiency of optical proximity correction.

[0046] As an example, the step of performing global optical proximity correction processing on multiple original graphics 100 includes: dividing the edges corresponding to the contours of the original graphics 100 into multiple first line segments (not shown), each first line segment including two endpoints (not shown) and a first sampling point (not shown) located between the two endpoints; and using the multiple first line segments, performing global optical proximity correction processing on the original graphics 100 until the absolute value of the edge placement error at the first sampling point is within a first threshold range.

[0047] In the process of optical proximity correction of the original graphic 100, in order to reduce the arbitrariness of edge movement, the position of line segments is adjusted (e.g., line segments are translated) to reduce edge placement error.

[0048] Specifically, the first sampling point is used as the specific location for comparing the difference between the original image 100 and the first simulated image after exposure, thereby obtaining the edge position error for determining whether optical proximity correction is completed.

[0049] As an example, in the step of dividing the edge corresponding to the outline of the original graphic 100 into multiple first line segments, the first sampling point is located at the center of the first line segment.

[0050] Specifically, the first sampling point is located at the center of the first line segment, which is intuitive, easy to detect, and simple to operate.

[0051] In this embodiment, model-based optical proximity correction (MB-OPC) is used to perform global optical proximity correction on the original pattern 100. During the correction process, an optical model and a photoresist photochemical reaction model are used to calculate the initial simulated pattern of the original pattern 100 after exposure. The model-based optical proximity correction process identifies the edges corresponding to the contour of the original pattern 100. The initial simulated pattern after exposure is compared with the identified contour of the original pattern 100, and the difference between them is called the edge placement error (EPE). The edge placement error is an indicator used to measure the correction quality. The smaller the edge placement error, the closer the exposed pattern is to the original pattern 100.

[0052] Continue to refer to Figure 3 Step S31: Determine whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

[0053] It should be noted that by judging whether the edge placement error of the plurality of first simulated graphics meets the correction standard, the first simulated graphics whose edge placement error meets the correction standard can be screened out, and the initial correction graphic 101 corresponding to the first simulated graphic can also be screened out. The screened initial correction graphic 101 can be used as the photomask graphic. In the subsequent local optical proximity correction processing, the screened initial correction graphic 101 is not used as the graphic to be corrected, thereby reducing the graphic correction amount of the local optical proximity correction processing and improving the efficiency of the optical proximity correction processing.

[0054] refer to Figure 4 Step S3: Obtain the first simulated graphic whose edge placement error does not meet the correction standard, and the corresponding initial correction graphic 101, and use the initial correction graphic 101 as the graphic to be corrected 103.

[0055] Specifically, by acquiring the first simulated image whose edge placement error does not meet the correction standard, and the corresponding initial correction image 101, it is beneficial to directly perform optical proximity correction on the image to be corrected 103, thereby reducing the running time of each optical proximity correction step and improving the running efficiency of the optical proximity correction step.

[0056] As an example, the step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard includes: obtaining the edge placement error of the first simulated graphic at each of the endpoint positions that does not meet the first preset condition, wherein the first preset condition is δ1×δ2<0, δ1 is the edge placement error of the first simulated graphic at any endpoint of the first line segment, and δ2 is the edge placement error of the first simulated graphic at the other endpoint of the first line segment.

[0057] refer to Figure 5 Step S4: Perform multiple local optical proximity correction steps, the local optical proximity correction steps include: Step S41: Perform local optical proximity correction processing on the pattern 103 to be corrected to form an initial corrected pattern 105 and a second simulated pattern (not shown) corresponding to the initial corrected pattern 105; Step S42: Determine whether the edge placement error of the second simulated pattern meets the correction standard; Step S43: When the edge placement error of the second simulated pattern does not meet the correction standard, obtain the second simulated pattern whose edge placement error does not meet the correction standard, and the initial corrected pattern 105 corresponding to it, and use the initial corrected pattern 105 as the pattern 103 to be corrected in the next local optical proximity correction; Step S44: When the edge placement error of the second simulated pattern meets the correction standard, use the initial corrected pattern 105 as the photomask pattern.

[0058] Specifically, multiple local optical proximity correction processes are performed. Each local optical proximity correction process involves a second simulated pattern that does not meet the correction criteria, along with its corresponding initial corrected pattern 105. In other words, after each local optical proximity correction process, it is determined whether the edge placement error of the second simulated pattern meets the correction criteria. If the correction criteria are met, the initial corrected pattern 105 of that part is directly used as the mask pattern and does not enter the next local optical proximity correction process. Compared with the existing scheme of performing multiple global optical proximity corrections on all original patterns 100 to form a mask pattern, the present invention can continuously reduce the number of patterns 103 to be corrected in the local optical proximity correction process, thereby reducing the running time of the optical proximity correction method and improving the efficiency of the optical proximity correction method.

[0059] It should be noted that the steps of local optical proximity correction processing are similar to those of the aforementioned global optical proximity correction processing, and therefore will not be repeated here.

[0060] It should also be noted that after performing multiple local optical proximity correction steps, the optical proximity correction method further includes adding auxiliary patterns around the photomask pattern.

[0061] Specifically, the photomask pattern is an exposing pattern, and the auxiliary pattern is an exposing pattern. Therefore, the auxiliary pattern is a scattering bar (SB), and the linewidth of the auxiliary pattern is greater than or equal to the minimum linewidth of the mask writing rule, and less than or equal to the resolution of the photolithography process, so that the auxiliary pattern can be written into the template, but will not be exposed.

[0062] In this embodiment, scattering strips are set around the photomask pattern, which helps to improve light intensity contrast, reduce edge placement error (EPE), and also helps to increase the depth of focus, thereby improving the photolithography process window.

[0063] In this embodiment, the changes to the traditional optical proximity correction method are minor, and the compatibility is high.

[0064] Accordingly, the present invention also provides an optical proximity correction system. Figure 6 This is a functional block diagram of an embodiment of the optical proximity correction system of the present invention.

[0065] In this embodiment, the optical proximity correction system 200 includes: a providing module 201, used to provide an initial image layer, the initial image layer including multiple original graphics; a global optical proximity correction processing module 202, used to perform global optical proximity correction processing on the multiple original graphics to form multiple initial corrected graphics, and multiple first simulated graphics corresponding to the multiple initial corrected graphics; an acquisition module 204, used to acquire the first simulated graphics whose edge placement error does not meet the correction standard, and the corresponding initial corrected graphics, and use the initial corrected graphics as graphics to be corrected; and a local optical proximity correction module 205, used to perform multiple local optical proximity correction steps, wherein... The local optical proximity correction step includes: performing local optical proximity correction processing on the image to be corrected to form an initial corrected image and a second simulated image corresponding to the initial corrected image; determining whether the edge placement error of the second simulated image meets the correction standard; when the edge placement error of the second simulated image does not meet the correction standard, obtaining the second simulated image whose edge placement error does not meet the correction standard, and the initial corrected image corresponding to it, and using the initial corrected image as the image to be corrected in the next local optical proximity correction; when the edge placement error of the second simulated image meets the correction standard, using the initial corrected image as the photomask image.

[0066] Specifically, the original image is first subjected to a global optical proximity correction process to form multiple initial corrected images and multiple first simulated images corresponding to the multiple initial corrected images. Then, the first simulated image whose edge placement error does not meet the correction standard is obtained, and its corresponding initial corrected image is obtained. The initial corrected image is used as the image to be corrected. Then, multiple local optical proximity correction processes are performed. Each local optical proximity correction process is a second simulated image that does not meet the correction standard, and its corresponding initial corrected image. That is, after each local optical proximity correction process, it is determined whether the edge placement error of the second simulated image meets the correction standard. If it meets the correction standard, the initial corrected image of that part is directly used as the mask image and does not enter the next local optical proximity correction process. Compared with the scheme of performing multiple global optical proximity corrections on all original images to form mask images, the embodiments of the present invention can continuously reduce the number of images to be corrected in the local optical proximity correction process, thereby reducing the running time of the optical proximity correction method and improving the efficiency of the optical proximity correction method.

[0067] The original pattern refers to the design pattern, which serves as a reference for the edge placement error of the exposure pattern obtained from the photolithography simulation.

[0068] After optical proximity correction is performed on the original pattern, the resulting pattern is used to create a photomask, which is then used for photolithography to form the corresponding photomask pattern on the wafer.

[0069] The global optical proximity correction processing module 202 performs global optical proximity correction processing on multiple original graphics, so that each original graphic can be corrected and compensated, thereby reducing the edge placement error of multiple initial corrected graphics and significantly improving the optical proximity effect.

[0070] It should be noted that by performing global optical proximity correction processing on multiple original graphics, it is beneficial to subsequently obtain the first simulated graphics whose edge placement error does not meet the correction standard, as well as the corresponding initial corrected graphics. Thus, in the subsequent local optical proximity correction processing, only the initial corrected graphics corresponding to the first simulated graphics that do not meet the correction standard are corrected, reducing the number of graphics processed in the optical proximity correction processing and improving the operating efficiency of optical proximity correction.

[0071] As an example, the step of performing global optical proximity correction processing on multiple original graphics includes: dividing the edges corresponding to the contours of the original graphics into multiple first line segments, each first line segment including two endpoints and a first sampling point located between the two endpoints; and using the multiple first line segments, performing global optical proximity correction processing on the original graphics until the absolute value of the edge placement error at the first sampling point is within a first threshold range.

[0072] In the process of optical proximity correction of the original pattern, in order to reduce the arbitrariness of edge movement, the position of line segments is adjusted (e.g., line segments are translated) to reduce edge placement error.

[0073] Specifically, the first sampling point is used as the specific location for comparing the difference between the original image and the first simulated image after exposure, thereby obtaining the edge position error used to determine whether optical proximity correction is completed.

[0074] As an example, in the step of dividing the edge corresponding to the outline of the original graphic into multiple first line segments, the first sampling point is located at the center of the first line segment.

[0075] Specifically, the first sampling point is located at the center of the first line segment, which is intuitive, easy to detect, and simple to operate.

[0076] In this embodiment, model-based optical proximity correction (MB-OPC) is used to perform global optical proximity correction on the original image. During the correction process, an optical model and a photoresist photochemical reaction model are used to calculate the initial simulated image after exposure of the original image. The model-based optical proximity correction process identifies the edges corresponding to the contours of the original image. The initial simulated image after exposure is compared with the identified contours of the original image, and the difference between them is called the edge placement error (EPE). Edge placement error is an indicator used to measure the quality of correction; the smaller the edge placement error, the closer the exposed image is to the original image.

[0077] In this embodiment, the optical proximity correction system 200 further includes a judgment module 203, used to determine whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

[0078] It should be noted that by judging whether the edge placement error of the plurality of first simulated graphics meets the correction standard, the first simulated graphics whose edge placement error meets the correction standard can be screened out, and the initial correction graphic corresponding to the first simulated graphic can also be screened out. The screened initial correction graphic can be used as the photomask graphic. In the subsequent local optical proximity correction process, the screened initial correction graphic is not used as the graphic to be corrected, thereby reducing the graphic correction amount of the local optical proximity correction process and improving the efficiency of the optical proximity correction process.

[0079] Specifically, the acquisition module 204 acquires the first simulated image whose edge placement error does not meet the correction standard, as well as the corresponding initial correction image, which facilitates the subsequent direct optical proximity correction of the image to be corrected, reducing the running time of each optical proximity correction step and improving the running efficiency of the optical proximity correction step.

[0080] As an example, the step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard includes: obtaining the edge placement error of the first simulated graphic at each of the endpoint positions that does not meet the first preset condition, wherein the first preset condition is δ1×δ2<0, δ1 is the edge placement error of the first simulated graphic at any endpoint of the first line segment, and δ2 is the edge placement error of the first simulated graphic at the other endpoint of the first line segment.

[0081] Specifically, the local optical proximity correction processing module performs multiple local optical proximity correction processes. Each local optical proximity correction process involves a second simulated image that does not meet the correction criteria, along with its corresponding initial corrected image. In other words, after each local optical proximity correction process, it is determined whether the edge placement error of the second simulated image meets the correction criteria. If it does, the initial corrected image of that part is directly used as the mask image and does not proceed to the next local optical proximity correction process. Compared to the existing scheme that performs multiple global optical proximity corrections on all original images to form a mask image, this embodiment of the invention can continuously reduce the number of images to be corrected in the local optical proximity correction process, thereby reducing the running time of the optical proximity correction method and improving its efficiency.

[0082] It should be noted that the steps of local optical proximity correction processing are similar to those of the aforementioned global optical proximity correction processing, and therefore will not be repeated here.

[0083] As an example, the optical proximity correction system 200 also includes an addition module 206 for adding auxiliary patterns around the photomask pattern.

[0084] Specifically, the photomask pattern is an exposing pattern, and the auxiliary pattern is an exposing pattern. Therefore, the auxiliary pattern is a scattering bar (SB), and the linewidth of the auxiliary pattern is greater than or equal to the minimum linewidth of the mask writing rule, and less than or equal to the resolution of the photolithography process, so that the auxiliary pattern can be written into the template, but will not be exposed.

[0085] In this embodiment, scattering strips are set around the photomask pattern, which helps to improve light intensity contrast, reduce edge placement error (EPE), and also helps to increase the depth of focus, thereby improving the photolithography process window.

[0086] In this embodiment, the modifications to the traditional optical proximity correction system 200 are minor, and the system has high compatibility.

[0087] Accordingly, the present invention also provides a photomask, comprising: a pattern obtained using the optical proximity correction method provided in the embodiments of the present invention.

[0088] This invention also provides a device that can implement the optical proximity correction method provided in this invention by loading a program, as described above. An optional hardware structure of the terminal device provided in this invention can be as follows: Figure 7 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.

[0089] 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.

[0090] 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.

[0091] This invention also provides a storage medium storing one or more computer instructions for implementing the optical proximity correction method provided in this invention.

[0092] 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.

[0093] 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.

[0094] 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 version layer is provided, which includes multiple original graphics; Global optical proximity correction is performed on multiple original images to form multiple initial corrected images and multiple first simulated images corresponding to the multiple initial corrected images; Obtain the first simulated image whose edge placement error does not meet the correction standard, and the corresponding initial correction image, and use the initial correction image as the image to be corrected; Perform multiple local optical proximity correction steps, the local optical proximity correction steps including: The image to be corrected is subjected to local optical proximity correction processing to form an initial corrected image and a second simulated image corresponding to the initial corrected image; Determine whether the edge placement error of the second simulated graphic meets the correction standard; When the edge placement error of the second simulated image does not meet the correction standard, the second simulated image whose edge placement error does not meet the correction standard and its corresponding initial corrected image are obtained, and the initial corrected image is used as the image to be corrected in the next local optical proximity correction. When the edge placement error of the second simulated graphic meets the correction standard, the initial corrected graphic is used as the photomask graphic.

2. The optical proximity correction method as described in claim 1, characterized in that, The step of performing global optical proximity correction processing on multiple original graphics includes: dividing the edges corresponding to the contours of the original graphics into multiple first line segments, each first line segment including two endpoints and a first sampling point located between the two endpoints; and using the multiple first line segments to perform global optical proximity correction processing on the original graphics until the absolute value of the edge placement error at the first sampling point is within a first threshold range.

3. The optical proximity correction method as described in claim 2, characterized in that, In the step of dividing the edge corresponding to the outline of the original graphic into multiple first line segments, the first sampling point is located at the center of the first line segment.

4. The optical proximity correction method as described in claim 2, characterized in that, The step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard includes: obtaining the edge placement error of the first simulated graphic at each endpoint position that does not meet the first preset condition, wherein the first preset condition is δ1×δ2<0, δ1 is the edge placement error of the first simulated graphic at any endpoint of the first line segment, and δ2 is the edge placement error of the first simulated graphic at the other endpoint of the first line segment.

5. The optical proximity correction method as described in claim 1, characterized in that, Before the step of obtaining the first simulated graphic whose edge placement error does not meet the correction standard, and the corresponding initial corrected graphic, the method further includes: determining whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

6. The optical proximity correction method as described in claim 1, characterized in that, After performing multiple local optical proximity correction steps, the optical proximity correction method further includes adding auxiliary patterns around the photomask pattern.

7. The optical proximity correction method as described in claim 6, characterized in that, In the step of adding auxiliary patterns around the photomask pattern, the auxiliary patterns are scattering strips, and the linewidth of the auxiliary patterns is greater than or equal to the minimum linewidth of the mask writing rules, and less than or equal to the resolution of the photolithography process.

8. An optical proximity correction system, characterized in that, include: A module is provided for providing an initial version layer, which includes multiple original graphics; A global optical proximity correction processing module is used to perform global optical proximity correction processing on multiple original images to form multiple initial corrected images and multiple first simulated images corresponding to the multiple initial corrected images; The acquisition module is used to acquire the first simulated image whose edge placement error does not meet the correction standard, and the corresponding initial correction image, and to use the initial correction image as the image to be corrected; A local optical proximity correction module is used to perform multiple local optical proximity correction steps. The local optical proximity correction steps include: performing local optical proximity correction processing on the image to be corrected to form an initial corrected image and a second simulated image corresponding to the initial corrected image. Determine whether the edge placement error of the second simulated image meets the correction standard; when the edge placement error of the second simulated image does not meet the correction standard, obtain the second simulated image whose edge placement error does not meet the correction standard, and its corresponding initial corrected image, and use the initial corrected image as the image to be corrected in the next local optical proximity correction; when the edge placement error of the second simulated image meets the correction standard, use the initial corrected image as the photomask image.

9. The optical proximity correction system as described in claim 8, characterized in that, The optical proximity correction system further includes a judgment module, used to determine whether the edge placement error of the plurality of first simulated graphics meets the correction standard.

10. The optical proximity correction system as claimed in claim 8, characterized in that, The optical proximity correction system further includes an addition module for adding auxiliary patterns around the photomask pattern.

11. A photomask, characterized in that, include: The image obtained using the optical proximity correction method as described in any one of claims 1-7.

12. 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 1-7.

13. 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 1-7.

14. 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 to 7.

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