Optical proximity correction method and system thereof, and mask manufacturing method

Abstract

This disclosure relates to an optical proximity correction method and system, and a photomask fabrication method. The optical proximity correction method includes: obtaining a photomask design layout; determining a one-dimensional region and a two-dimensional region within the photomask design layout; using a pattern within the one-dimensional region as a first target pattern for optical proximity correction; performing a first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model to obtain a first reference layout of the photomask; using a pattern within the two-dimensional region as a second target pattern for optical proximity correction; performing a second optical proximity correction on the second target pattern using a two-dimensional optical proximity correction model to obtain a second reference layout of the photomask; and merging the first and second reference layouts of the photomask to obtain the photomask layout. The above-mentioned optical proximity correction method is beneficial for saving photomask costs and reducing R&D and process costs.

Description

Technical Field

[0001] This disclosure relates to the field of integrated circuit technology, and in particular to an optical proximity correction method and system thereof, and a photomask fabrication method. Background Technology

[0002] Dynamic Random Access Memory (DRAM) is a semiconductor memory that allows for high-speed, random writing and reading of data and is widely used in data storage devices.

[0003] However, one-dimensional and two-dimensional patterns in DRAM have different requirements for line-edgeroughness (LER), critical dimension uniformity (CDU), and process window (PW). Therefore, to improve the feasibility of DRAM production, it is often necessary to design separate photomask patterns for one-dimensional and two-dimensional patterns, requiring two exposures. This can easily lead to increased photomask costs, R&D costs, and process costs. Summary of the Invention

[0004] Based on this, the present disclosure provides an optical proximity correction method and system, as well as a photomask fabrication method, which helps to save photomask costs and reduce R&D and process costs, while improving the efficiency of optical proximity correction (Manual Optical Proximity Correction, or Manual OPC) to effectively improve the production efficiency and yield of DRAM.

[0005] To achieve the above objectives, some embodiments of this disclosure provide an optical proximity correction method, including the following steps.

[0006] Obtain the photomask design layout and determine the one-dimensional and two-dimensional regions within the photomask design layout.

[0007] The pattern within a one-dimensional region is used as the first target pattern for optical proximity correction. The first target pattern is then subjected to first optical proximity correction using a one-dimensional optical proximity correction model to obtain the first reference pattern of the photomask.

[0008] The pattern within the two-dimensional region is used as the second target pattern for optical proximity correction. The second target pattern is then subjected to second optical proximity correction using a two-dimensional optical proximity correction model to obtain the second reference pattern of the photomask.

[0009] The first reference pattern and the second reference pattern of the photomask are merged to obtain the photomask layout.

[0010] In some embodiments, determining the one-dimensional and two-dimensional regions in the photomask design layout includes: obtaining a one-dimensional pattern definition layer; aligning and overlapping the one-dimensional pattern definition layer and the photomask design layout; wherein, the area of ​​the photomask design layout covered by the pattern in the one-dimensional pattern definition layer is a one-dimensional region, and the area of ​​the photomask design layout not covered by the pattern in the one-dimensional pattern definition layer is a two-dimensional region.

[0011] In some embodiments, merging the first reference pattern and the second reference pattern of the photomask to obtain a photomask layout includes: performing optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask respectively; and merging the first reference pattern and the second reference pattern of the photomask after the optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask are qualified to obtain a photomask layout.

[0012] In some embodiments, the optical proximity correction method further includes: in the process of using a one-dimensional optical proximity correction model to perform a first optical proximity correction on the first target pattern with a pattern in a one-dimensional region as the first target pattern for optical proximity correction, using a pattern in a two-dimensional region as the optical environment reference factor for the first optical proximity correction; and in the process of using a two-dimensional optical proximity correction model to perform a second optical proximity correction on the second target pattern with a pattern in a two-dimensional region as the second target pattern for optical proximity correction, using a first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction.

[0013] In some embodiments, the minimum distance between the pattern in the one-dimensional region and the pattern in the two-dimensional region is less than the optical influence range of the optical proximity correction.

[0014] In other embodiments, the minimum distance between the patterns in the one-dimensional region and the patterns in the two-dimensional region is greater than the optical influence range of the optical proximity correction. A first optical proximity correction is performed on the first target pattern using a one-dimensional optical proximity correction model, and a second optical proximity correction is performed on the second target pattern using a two-dimensional optical proximity correction model, simultaneously.

[0015] In some embodiments, the first target pattern and the second target pattern are located on the same layer. The one-dimensional optical proximity correction model and the two-dimensional optical proximity correction model are established based on the same process parameters and are obtained by debugging based on the same reference standard measurement point.

[0016] On the other hand, embodiments of this disclosure also provide an optical proximity correction system, including: a pattern recognition unit, a pattern correction unit, and a pattern processing unit. The pattern recognition unit is configured to: acquire a photomask design layout and determine a one-dimensional region and a two-dimensional region within the photomask design layout. The pattern correction unit is connected to the pattern recognition unit and is configured to: use the pattern within the one-dimensional region as a first target pattern for optical proximity correction, perform a first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model, and obtain a first reference layout of the photomask; use the pattern within the two-dimensional region as a second target pattern for optical proximity correction, perform a second optical proximity correction on the second target pattern using a two-dimensional optical proximity correction model, and obtain a second reference layout of the photomask. The pattern processing unit is connected to the pattern correction unit and is configured to: merge the first reference layout of the photomask and the second reference layout of the photomask to obtain a photomask layout.

[0017] In some embodiments, the optical proximity correction system further includes a pattern detection unit. The pattern detection unit is connected to the pattern correction unit and the pattern processing unit, respectively, and is configured to perform optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask, respectively, so as to send a pattern merging instruction to the pattern processing unit after the optical manufacturability checks of the first reference pattern and the second reference pattern of the photomask are qualified.

[0018] In another aspect, embodiments of this disclosure also provide a method for fabricating a photomask, wherein a photomask pattern is obtained according to the optical proximity correction method described in some of the foregoing embodiments, so as to form the photomask pattern in the photomask.

[0019] The optical proximity correction method and system, and the photomask fabrication method provided in this disclosure are as described above. In this disclosure, one-dimensional and two-dimensional regions in the photomask design layout can be distinguished. A one-dimensional optical proximity correction model is applied to the pattern in the one-dimensional region to obtain a first reference photomask layout, and a two-dimensional optical proximity correction model is applied to the pattern in the two-dimensional region to obtain a second reference photomask layout. The corrected first and second reference photomask layouts are then merged to obtain the final photomask layout. Thus, this disclosure allows for the application of different optical proximity correction models to the patterns in the one-dimensional and two-dimensional regions, and the merging of these models to obtain the final photomask layout. This eliminates the need to provide separate photomask design layouts and photomasks for one-dimensional and two-dimensional graphics and to perform corresponding processes. Therefore, this disclosure can effectively save photomask costs and reduce R&D and process costs, while improving the efficiency of Manual Optical Proximity Correction (Manual OPC), thereby effectively improving DRAM production efficiency and yield. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or conventional technologies of this disclosure, the accompanying drawings used in the description of the embodiments or conventional technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart of an optical proximity correction method provided in some embodiments;

[0022] Figure 2 This is a schematic diagram of the structure of a Block and Chip in a DRAM provided in some embodiments;

[0023] Figure 3 for Figure 1 A schematic diagram of the execution process of step S100 in the optical proximity correction method shown;

[0024] Figure 4 Figure (a) is a schematic diagram of the distribution of patterns within a one-dimensional region provided in some embodiments;

[0025] Figure 4 Figure (b) is a schematic diagram of the distribution of patterns within a two-dimensional region provided in some embodiments;

[0026] Figure 5 for Figure 1 A schematic diagram of the execution process of another step S100 in the optical proximity correction method shown;

[0027] Figure 6 A flowchart of an optical proximity correction method provided in some other embodiments;

[0028] Figure 7 Here is a flowchart of an optical proximity correction method provided in some of the embodiments;

[0029] Figure 8 Here are some structural examples of an optical proximity correction system provided in some embodiments;

[0030] Figure 9 This is a structural example diagram of another optical proximity correction system provided in some embodiments.

[0031] Explanation of reference numerals in the attached figures:

[0032] Chip - chip; Cell - array unit; Peri - edge area; R - functional area; SA - sensing amplifier circuit; SWD - word line drive circuit; L - one-dimensional pattern definition layer; F0 - one-dimensional pattern definition pattern; F1 - one-dimensional pattern; F2 - two-dimensional pattern.

[0033] 1-Pattern recognition unit, 2-Pattern correction unit, 3-Pattern processing unit, 4-Pattern detection unit;

[0034] 21 - One-dimensional pattern correction module, 22 - Two-dimensional pattern correction module. Detailed Implementation

[0035] To facilitate understanding of this disclosure, a more complete description will now be given with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are shown. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0037] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this invention, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0038] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms “comprise” and / or “comprising” are used in this specification, the presence of the stated feature, integer, step, operation, element, and / or part is established, but the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups is not excluded. Meanwhile, when used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0039] Please see Figure 1 This disclosure provides an optical proximity correction method in some embodiments, including steps S100 to S400.

[0040] S100: Obtain the photomask design layout and determine the one-dimensional and two-dimensional regions in the photomask design layout.

[0041] S200, the pattern in the one-dimensional region is used as the first target pattern for optical proximity correction, and the first target pattern is subjected to first optical proximity correction using a one-dimensional optical proximity correction model to obtain the first reference pattern of the photomask.

[0042] S300, the pattern in the two-dimensional region is used as the second target pattern for optical proximity correction. The two-dimensional optical proximity correction model is used to perform second optical proximity correction on the second target pattern to obtain the second reference pattern of the photomask.

[0043] S400 merges the first reference pattern and the second reference pattern of the photomask to obtain the photomask pattern.

[0044] In this embodiment, the one-dimensional and two-dimensional regions of the photomask design layout can be distinguished. A one-dimensional optical proximity correction model is applied to the pattern within the one-dimensional region to obtain a first reference photomask layout, and a two-dimensional optical proximity correction model is applied to the pattern within the two-dimensional region to obtain a second reference photomask layout. The corrected first and second reference photomask layouts are then merged to obtain the final photomask layout. Thus, this embodiment can apply different optical proximity correction models to the patterns in the one-dimensional and two-dimensional regions and merge them to obtain the photomask layout, eliminating the need for separate photomask design layouts and photomasks for one-dimensional and two-dimensional patterns and for performing corresponding processes. Therefore, this embodiment can effectively save photomask costs and reduce R&D and process costs, while improving the efficiency of Manual Optical Proximity Correction (Manual OPC), thereby effectively improving DRAM production efficiency and yield.

[0045] It should be added that the above-mentioned one-dimensional and two-dimensional regions are divided according to the degree of regularity of the pattern arrangement; wherein, a pattern arranged with a fixed period in both the first and second directions is a one-dimensional pattern, and the region containing such a one-dimensional pattern is a one-dimensional region; a pattern arranged irregularly in the first and / or second directions is a two-dimensional pattern, and the region containing such a two-dimensional pattern is a two-dimensional region. The first and second directions intersect, for example, orthogonally.

[0046] In some embodiments, determining the one-dimensional and two-dimensional regions in the photomask design layout in step S100 includes: obtaining a one-dimensional pattern definition layer; aligning and overlapping the one-dimensional pattern definition layer and the photomask design layout; wherein, the area of ​​the photomask design layout covered by the pattern in the one-dimensional pattern definition layer is the one-dimensional region, and the area of ​​the photomask design layout not covered by the pattern in the one-dimensional pattern definition layer is the two-dimensional region.

[0047] Here, the pattern in the one-dimensional pattern definition layer is a one-dimensional pattern definition pattern, which can be matched and obtained according to requirements.

[0048] In this embodiment of the present disclosure, the one-dimensional pattern definition layer can be pre-stored or obtained simultaneously with the acquisition of the photomask design layout. After acquiring the one-dimensional pattern definition layer, this embodiment of the present disclosure facilitates the quick and easy definition of one-dimensional regions (i.e., one-dimensional patterns) and two-dimensional regions (i.e., two-dimensional patterns) during optical proximity correction by aligning and overlapping the one-dimensional pattern definition layer and the photomask design layout, thereby improving the efficiency of optical proximity correction.

[0049] Please see Figures 2-4 In the following embodiments, the layout diagram in DRAM manufacturing is used as an example to illustrate in detail the one-dimensional region, the two-dimensional region, and the one-dimensional pattern definition layer. The first direction is the X direction, and the second direction is the Y direction.

[0050] Please see Figure 2Multiple chips can be arrayed to achieve integrated manufacturing, with the area between adjacent chips forming a frame. This chip array and frame area, for example, corresponds to the target exposure area for optical proximity correction. When magnified, any chip area can have one or more array regions and corresponding edge regions (Peri). Each chip array region can contain multiple array cells and a functional area R adjacent to the array cells. This functional area R can house signal sensing circuits and control circuits, such as a sense amplifier (SA) and a sub-word line driver (SWD). Thus, these areas can be categorized into one-dimensional and two-dimensional regions based on the regularity of their internal patterns, corresponding to one-dimensional (1D) and two-dimensional (2D) patterns.

[0051] Please see Figure 3 The one-dimensional pattern definition layer L is obtained based on the layout of the aforementioned chip. After obtaining the one-dimensional pattern definition layer L, the one-dimensional pattern definition layer L and the photomask design layout (e.g., the layout of the aforementioned chip) can be aligned and overlapped; wherein, the area of ​​the photomask design layout (e.g., the layout of the aforementioned chip) covered by the pattern in the one-dimensional pattern definition layer L (i.e., the one-dimensional pattern definition pattern F0) is a one-dimensional region, and the area of ​​the photomask design layout (e.g., the layout of the aforementioned chip) not covered by the pattern in the one-dimensional pattern definition layer (i.e., the one-dimensional pattern definition pattern F0) is a two-dimensional region.

[0052] Therefore, as Figure 4 As shown in Figure (a), the region where the array cell is located is a one-dimensional region. The pattern within the array cell is a one-dimensional pattern F1, which can be arranged according to a fixed period in both the X and Y directions. Figure 4 As shown in Figure (b), the area containing the edge region Peri and the functional region R (e.g., the area where the sensing amplifier circuit SA and the word line drive circuit SWD are located) is a two-dimensional region. The pattern in the edge region Peri and the functional region R is the two-dimensional pattern F2. The two-dimensional pattern F1 is irregularly arranged in the X direction and / or Y direction.

[0053] It is understood that the one-dimensional pattern definition pattern F0 in the one-dimensional pattern definition layer L can be different depending on the matching photomask design layout. For other embodiments, please refer to... Figure 5The one-dimensional pattern definition layer L is obtained based on the layout of the aforementioned chip integration distribution. The one-dimensional pattern definition pattern F0 in the one-dimensional pattern definition layer L can also be distributed in the area where the cut channel is located. This disclosure does not limit this aspect.

[0054] It is worth mentioning that, in some embodiments, please refer to Figure 6 and Figure 7 In step S400, the first reference pattern and the second reference pattern of the photomask are merged to obtain the photomask layout. This includes: performing an optical manufacturability check (LMC) on the first reference pattern and the second reference pattern of the photomask respectively; and merging the first reference pattern and the second reference pattern of the photomask after the optical manufacturability check of the first reference pattern and the second reference pattern of the photomask is qualified to obtain the photomask layout.

[0055] In this embodiment of the disclosure, by first performing an optical manufacturability check on the modified first reference photomask and second reference photomask, the manufacturability of the first reference photomask and second reference photomask can be ensured, so that the photomask layout obtained after merging the first reference photomask and second reference photomask can have better manufacturability, thereby helping to improve the production efficiency and production yield of DRAM.

[0056] In some embodiments, please refer to Figure 6 The optical proximity correction method further includes: in the process of using a one-dimensional optical proximity correction model to perform first optical proximity correction on the first target pattern, with the pattern in the one-dimensional region as the first target pattern, using the one-dimensional optical proximity correction model to perform first optical proximity correction, using the pattern in the two-dimensional region as the optical environment reference factor for the first optical proximity correction. In the process of using a two-dimensional optical proximity correction model to perform second optical proximity correction on the second target pattern, with the pattern in the two-dimensional region as the second target pattern, using the first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction.

[0057] For example, such as Figure 6 As shown, step S200 may include steps S210 to S240.

[0058] S210 uses the pattern within the one-dimensional region as the first target pattern for optical proximity correction.

[0059] S220 uses the pattern of the two-dimensional region as an optical environment reference factor for the first optical proximity correction.

[0060] S230, a one-dimensional optical proximity correction model is used to perform the first optical proximity correction on the first target pattern.

[0061] S240, obtained the first reference layout of the photomask.

[0062] Here, there is no requirement for the order of steps S210 and S220; either step can be performed first, or they can be performed simultaneously.

[0063] For example, such as Figure 6 As shown, step S300 may include steps S310 to S340.

[0064] S310 uses the first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction.

[0065] S320 uses the pattern within the two-dimensional region as the second target pattern for optical proximity correction.

[0066] S330 uses a two-dimensional optical proximity correction model to perform second optical proximity correction on the second target pattern.

[0067] S340, obtained the second reference layout of the photomask.

[0068] Here, there is no requirement for the order of steps S310 and S320; either step can be performed first, or they can be performed simultaneously.

[0069] It should be added that in some of the above embodiments, the use of a one-dimensional optical proximity correction model to perform first optical proximity correction on the first target pattern, and the use of a two-dimensional optical proximity correction model to perform second optical proximity correction on the second target pattern, are both model-based optical proximity corrections. Furthermore, the aforementioned use of the two-dimensional pattern as the optical environment reference factor for the first optical proximity correction, and the use of the first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction, means that the two-dimensional pattern and the first reference pattern of the photomask can be used as reference layers for calculating the optical environment during the corresponding optical proximity correction.

[0070] In some embodiments, after performing a first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model to obtain a first reference pattern of the photomask, an OPC repair script can be used on the two-dimensional optical proximity correction model to use the first reference pattern of the photomask as an optical environment reference factor for the second optical proximity correction. Furthermore, in this step, it is necessary not only to maintain the pattern stability of the first reference pattern of the photomask, but also to simultaneously satisfy the OPC convergence of the one-dimensional and two-dimensional regions. The convergence condition of this OPC convergence can be set to match the requirements.

[0071] Furthermore, in some embodiments, the first target pattern and the second target pattern are located on the same layer. The one-dimensional optical proximity correction model and the two-dimensional optical proximity correction model are established based on the same process parameters and obtained by debugging based on the same reference standard measurement point.

[0072] It is understood that the one-dimensional optical proximity correction model and the two-dimensional optical proximity correction model are two independent models. If they are applied to the optical proximity correction of patterns in the same layer (e.g., the same photolithographic pattern layer), there will be some differences in the optimal process energy and optimal focus value in the one-dimensional and two-dimensional optical proximity correction models. Therefore, in this embodiment, the one-dimensional and two-dimensional optical proximity correction models are established based on the same process parameters (e.g., simulation using data obtained from exposure with the same set of process parameters) and are obtained by debugging based on the same reference standard measurement point (anchor gauge). This can effectively avoid the differences between the one-dimensional and two-dimensional optical proximity correction models, which is beneficial for the subsequent merging of the first and second reference patterns of the photomask after correction.

[0073] Here, the reference standard measurement point in the corresponding optical proximity correction model is used to define the intensity threshold of the photoresist surface, which corresponds to the exposure conditions of the model data in the process. If the reference standard measurement point is the same for both the one-dimensional and two-dimensional optical proximity correction models, it indicates that their exposure conditions in the process are identical. Therefore, the key to whether the same photomask design layout can be corrected using both one-dimensional and two-dimensional optical proximity correction models lies in whether the one-dimensional and two-dimensional optical proximity correction models are established using the same process parameters and calibrated using the same reference standard measurement point.

[0074] It is worth mentioning that some of the above embodiments employ, for example... Figure 6 The optical proximity correction method is illustrated. In these embodiments, optionally, the minimum distance between the pattern in the one-dimensional region and the pattern in the two-dimensional region is less than the optical influence range (OPC model ambit) of the optical proximity correction.

[0075] For example, the optical effect range of optical proximity correction. Where λ is the wavelength of the exposure beam, NA is the numerical aperture of the imaging objective, and Pixel Count is the number of pixels.

[0076] In other embodiments, please refer to Figure 7The minimum distance between the patterns in the one-dimensional region and the patterns in the two-dimensional region is greater than the optical influence range of optical proximity correction. Thus, the optical diffraction and refraction of the patterns in the one-dimensional and two-dimensional regions do not interfere with each other. The first optical proximity correction for the first target pattern using the one-dimensional optical proximity correction model, and the second optical proximity correction for the second target pattern using the two-dimensional optical proximity correction model, can be performed simultaneously. This effectively saves the running time of optical proximity correction, thereby improving its efficiency.

[0077] On the other hand, this disclosure also provides an optical proximity correction system for implementing the optical proximity correction methods described in some of the above embodiments. This optical proximity correction system also possesses all the technical advantages of the aforementioned optical proximity correction methods, and will not be detailed here.

[0078] Please see Figure 8 In some embodiments of this disclosure, the optical proximity correction system includes: a pattern recognition unit 1, a pattern correction unit 2, and a pattern processing unit 3. The pattern recognition unit 1 is configured to: acquire a photomask design layout and determine a one-dimensional region and a two-dimensional region within the photomask design layout. The pattern correction unit 2 is connected to the pattern recognition unit 1 and is configured to: use the pattern within the one-dimensional region as a first target pattern for optical proximity correction, perform a first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model, and obtain a first reference layout of the photomask; use the pattern within the two-dimensional region as a second target pattern for optical proximity correction, perform a second optical proximity correction on the second target pattern using a two-dimensional optical proximity correction model, and obtain a second reference layout of the photomask. The pattern processing unit 3 is connected to the pattern correction unit 2 and is configured to: merge the first reference layout of the photomask and the second reference layout of the photomask to obtain a photomask layout.

[0079] In some embodiments, the pattern recognition unit 1 pre-stores a one-dimensional pattern definition layer, and the pattern recognition unit 1 is further configured to: align and overlap the one-dimensional pattern definition layer and the photomask design layout, so as to identify the area of ​​the photomask design layout covered by the pattern in the one-dimensional pattern definition layer as a one-dimensional area, and the area of ​​the photomask design layout not covered by the pattern in the one-dimensional pattern definition layer as a two-dimensional area.

[0080] The meanings of one-dimensional and two-dimensional regions can be found in the relevant descriptions in some of the foregoing embodiments, and will not be elaborated here.

[0081] In some embodiments, please refer to Figure 9The optical proximity correction system also includes a pattern detection unit 4. The pattern detection unit 4 is connected to the pattern correction unit 2 and the pattern processing unit 3 respectively, and is configured to perform optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask respectively, so that after the optical manufacturability checks of the first reference pattern and the second reference pattern of the photomask are qualified, a pattern merging instruction is sent to the pattern processing unit 3.

[0082] In some embodiments, please continue reading Figure 9 The pattern correction unit 2 includes a one-dimensional pattern correction module 21 and a two-dimensional pattern correction module 22. The one-dimensional pattern correction module 21 is connected to the pattern recognition unit 1 and the pattern detection unit 4, and is configured to: use the pattern within the one-dimensional region as the first target pattern for optical proximity correction, and perform first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model to obtain a first reference pattern for the photomask. The two-dimensional pattern correction module 22 is connected to the pattern recognition unit 1 and the pattern detection unit 4, and is configured to: use the pattern within the two-dimensional region as the second target pattern for optical proximity correction, and perform second optical proximity correction on the second target pattern using a two-dimensional optical proximity correction model to obtain a second reference pattern for the photomask.

[0083] In some embodiments, the one-dimensional pattern correction module 21 is further configured to: use the pattern in the one-dimensional region as the first target pattern for optical proximity correction, use the pattern in the two-dimensional region as the optical environment reference factor for the first optical proximity correction, and use the one-dimensional optical proximity correction model to perform the first optical proximity correction on the first target pattern to obtain the first reference pattern of the photomask.

[0084] In some embodiments, please continue reading Figure 9 The two-dimensional pattern correction module 22 is also connected to the one-dimensional pattern correction module 21. The two-dimensional pattern correction module 22 is also configured to: take the pattern in the two-dimensional region as the second target pattern for optical proximity correction, take the first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction, and use the two-dimensional optical proximity correction model to perform second optical proximity correction on the second target pattern to obtain the second reference pattern of the photomask.

[0085] Furthermore, in the optical proximity correction systems provided in some of the above embodiments, the terms "module" and "unit," as used in this specification, can be used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a "module" or "unit" can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a thread of execution, a program, and / or a computer. For example, a "module" or "unit" can be executed from various computer-readable media on which various data structures are stored.

[0086] In the embodiments provided in this disclosure, it should be understood that the disclosed "modules" or "units" can be implemented in other ways. For example, the apparatus described above is merely illustrative. For example, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or units may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the described interconnections may be through some interfaces, indirect coupling or communication connections between modules or units, and may be electrical, mechanical, or other forms. The separately described units or modules may or may not be physically separated. Some or all of the units or modules may be selected to achieve the purpose of the embodiments of this disclosure according to actual needs.

[0087] This disclosure also provides a method for fabricating a photomask, which can be fabricated based on the photomask pattern obtained by the optical proximity correction method described in some of the foregoing embodiments, so as to form a photomask pattern in the photomask.

[0088] In this embodiment, the photomask fabrication method is as described above. The technical effects achieved by this photomask fabrication method are the same as those achieved by the optical proximity correction method in the foregoing embodiments, and will not be described in detail here.

[0089] This disclosure also provides an electronic device including a memory and a processor. Computer instructions are stored in the memory. When executed by the processor, the computer instructions implement the optical proximity correction method as described in any of the foregoing embodiments.

[0090] This disclosure also provides a storage medium storing computer instructions executable by a processor, wherein the computer instructions, when executed by the processor, implement the optical proximity correction method as described in any of the foregoing embodiments.

[0091] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a readable storage medium, and when executed, it can implement the processes of the embodiments of the methods described above. Any reference to memory or other media used in the embodiments provided in this disclosure can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), floppy disk, flash memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The processors involved in the embodiments provided in this disclosure can be general-purpose processors, central processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited thereto.

[0092] In the aforementioned storage media and electronic devices, when computer instructions are executed by the processor, the optical proximity correction method described in any of the foregoing embodiments is employed. Thus, the use of optical proximity correction in the aforementioned storage media and electronic devices helps to save on photomask costs and reduce R&D and process costs, while simultaneously improving the efficiency of Manual Optical Proximity Correction (Manual OPC), thereby effectively improving the production efficiency and yield of DRAM.

[0093] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the scope of protection of this disclosure. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical proximity correction method characterized by, include: Obtain the photomask design layout and determine the one-dimensional and two-dimensional regions in the photomask design layout; The pattern within the one-dimensional region is used as the first target pattern for optical proximity correction. The first target pattern is then subjected to first optical proximity correction using a one-dimensional optical proximity correction model to obtain the first reference pattern of the photomask. The pattern within the two-dimensional region is used as the second target pattern for optical proximity correction. The second target pattern is then subjected to second optical proximity correction using a two-dimensional optical proximity correction model to obtain the second reference pattern of the photomask. The first reference pattern of the photomask and the second reference pattern of the photomask are merged to obtain the photomask layout; Wherein, the minimum distance between the pattern in the one-dimensional region and the pattern in the two-dimensional region is less than the optical influence range of optical proximity correction; when the pattern in the one-dimensional region is used as the first target pattern for optical proximity correction, and the one-dimensional optical proximity correction model is used to perform the first optical proximity correction on the first target pattern, the pattern in the two-dimensional region is used as the optical environment reference factor for the first optical proximity correction; when the pattern in the two-dimensional region is used as the second target pattern for optical proximity correction, and the two-dimensional optical proximity correction model is used to perform the second optical proximity correction on the second target pattern, the first reference pattern of the photomask is used as the optical environment reference factor for the second optical proximity correction. When the first reference pattern of the photomask is used as the optical environment reference factor for the second optical proximity correction, the pattern of the first reference pattern of the photomask is stable and simultaneously satisfies the OPC convergence of the one-dimensional region and the two-dimensional region.

2. The optical proximity correction method according to claim 1, characterized in that, Determining the one-dimensional and two-dimensional regions in the photomask design layout includes: Get the one-dimensional pattern definition layer; Align and overlap the one-dimensional pattern definition layer and the photomask design layout; The area of ​​the photomask design pattern covered by the pattern in the one-dimensional pattern definition layer is the one-dimensional region, and the area of ​​the photomask design pattern not covered by the pattern in the one-dimensional pattern definition layer is the two-dimensional region.

3. The optical proximity correction method according to claim 1, characterized in that, The step of merging the first reference pattern and the second reference pattern of the photomask to obtain the photomask layout includes: Optical manufacturability checks were performed on the first reference pattern and the second reference pattern of the photomask, respectively. After the optical manufacturability check of the first reference pattern and the second reference pattern of the photomask is passed, the first reference pattern and the second reference pattern of the photomask are merged to obtain the photomask pattern.

4. The optical proximity correction method according to claim 1, characterized in that, When the minimum distance between the pattern in the one-dimensional region and the pattern in the two-dimensional region is less than the optical influence range of optical proximity correction, the optical proximity correction method further includes: After performing the first optical proximity correction on the first target pattern using the one-dimensional optical proximity correction model and obtaining the first reference pattern of the photomask, an OPC repair script is used on the two-dimensional optical proximity correction model to use the first reference pattern of the photomask as the optical environment reference factor for the second optical proximity correction.

5. The optical proximity correction method according to any one of claims 1 to 4, characterized in that, The first target pattern and the second target pattern are located on the same layer; The one-dimensional optical proximity correction model and the two-dimensional optical proximity correction model are established based on the same process parameters and are obtained by debugging based on the same reference standard measurement point.

6. An optical proximity correction system, characterized in that, include: The pattern recognition unit is configured to: acquire a photomask design layout and determine a one-dimensional region and a two-dimensional region in the photomask design layout; The pattern correction unit, connected to the pattern recognition unit, is configured to: take the pattern in the one-dimensional region as the first target pattern for optical proximity correction, perform first optical proximity correction on the first target pattern using a one-dimensional optical proximity correction model, and obtain a first reference pattern of the photomask; take the pattern in the two-dimensional region as the second target pattern for optical proximity correction, perform second optical proximity correction on the second target pattern using a two-dimensional optical proximity correction model, and obtain a second reference pattern of the photomask. The pattern processing unit, connected to the pattern correction unit, is configured to: merge the first reference pattern of the photomask and the second reference pattern of the photomask to obtain a photomask pattern; Wherein, the minimum distance between the pattern in the one-dimensional region and the pattern in the two-dimensional region is less than the optical influence range of optical proximity correction; when the pattern in the one-dimensional region is used as the first target pattern for optical proximity correction, and the one-dimensional optical proximity correction model is used to perform the first optical proximity correction on the first target pattern, the pattern in the two-dimensional region is used as the optical environment reference factor for the first optical proximity correction; when the pattern in the two-dimensional region is used as the second target pattern for optical proximity correction, and the two-dimensional optical proximity correction model is used to perform the second optical proximity correction on the second target pattern, the first reference pattern of the photomask is used as the optical environment reference factor for the second optical proximity correction. When the first reference pattern of the photomask is used as the optical environment reference factor for the second optical proximity correction, the pattern of the first reference pattern of the photomask is stable and simultaneously satisfies the OPC convergence of the one-dimensional region and the two-dimensional region.

7. The optical proximity correction system according to claim 6, characterized in that, Also includes: The pattern detection unit, connected to the pattern correction unit and the pattern processing unit respectively, is configured to: perform optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask respectively, so as to send a pattern merging instruction to the pattern processing unit after the optical manufacturability checks on the first reference pattern and the second reference pattern of the photomask are qualified.

8. A method for fabricating a photomask, characterized in that, include: A photomask is fabricated using the photomask pattern obtained by the optical proximity correction method according to any one of claims 1 to 5, so as to form the photomask pattern in the photomask.

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