Optical proximity correction method and computer readable storage medium
Patent Information
- Application Number
- CN202611478993.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-22
- Publication Date
- 2026-10-30
AI Technical Summary
因此，传统修正技术中的OPC模型具有非常复杂和修正时间久的缺点
[0026]如上所述，本申请提供的光学临近效应校正方法及计算机可读存储介质包括：按照不同区域的局部图案线宽，对初始掩膜版中的目标图层进行区域划分，以获得局部图案线宽不同的若干个子图案区；对各所述子图案区中的图案进行边缘线段切分，且不同所述子图案区所对应的边缘线段切分步长不同；对各所述子图案区中的图案进行所述边缘线段切分后所获得的各边缘线段进行光学临近效应校正，且不同所述子图案区所采用的光学临近效应模型不同。
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Figure CN123010324A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to an optical proximity effect correction method and a computer-readable storage medium. Background Technology
[0002] With the development of integrated circuits, semiconductor manufacturing technology is constantly evolving towards smaller dimensions. The feature size of semiconductor devices is even smaller than the wavelength of light used in photolithography. In this situation, due to the diffraction effect of light, the pattern on the mask will be deformed during transfer, a phenomenon known as the optical proximity effect. The optical proximity effect causes a significant difference between the actual pattern projected onto the wafer and the designed target pattern, thus affecting the photolithography quality of adjacent pattern areas on the mask, and consequently impacting circuit performance and production yield.
[0003] To eliminate the effects of optical proximity, optical proximity correction (OPC) is commonly used. This method uses computer software to correct the original pattern on the semiconductor substrate to be exposed on the silicon wafer, resulting in a target pattern that differs from the original. A photomask is then fabricated based on this target pattern. During photolithography, the pattern projected onto the semiconductor substrate using this photomask is almost identical to the original pattern, thus compensating for the problems caused by optical proximity.
[0004] Currently, in the OPC modeling process, algorithms are used to simulate a series of optical effects and photoresist physicochemical effects in the lithography machine to optimize the corresponding algorithm coefficients and model thresholds. Therefore, the OPC model in traditional correction techniques has the disadvantages of being very complex and having a long correction time. Summary of the Invention
[0005] One objective of this application is to provide an optical proximity effect correction method and a computer-readable storage medium, and to propose a new edge segmentation method to simplify the optical proximity effect correction process and reduce the total correction time for the optical proximity effect.
[0006] In a first aspect, to achieve the above objectives, one embodiment of this application provides an optical proximity effect correction method, comprising:
[0007] Based on the line width of the local pattern in different areas, the target layer in the initial mask is divided into regions to obtain several sub-pattern areas with different line widths of the local pattern.
[0008] The patterns in each of the sub-pattern areas are segmented by edge lines, and the segmentation step size for the edge lines corresponding to different sub-pattern areas is different.
[0009] Optical proximity effect correction is performed on each edge segment obtained after dividing the pattern in each of the sub-pattern regions by the edge segment, and the optical proximity effect model used for different sub-pattern regions is different.
[0010] Furthermore, the sub-pattern area includes a first sub-pattern area, a second sub-pattern area, and a third sub-pattern area; the pattern in the first sub-pattern area has a first minimum line width, the pattern in the second sub-pattern area has a second minimum line width, and the pattern in the third sub-pattern area has a third minimum line width; the first minimum line width is smaller than the second minimum line width, and the second minimum line width is smaller than the third minimum line width.
[0011] Furthermore, the first minimum linewidth is less than or equal to half of the lithography machine exposure wavelength.
[0012] Furthermore, the segmentation step length of the edge line segments corresponding to the several sub-pattern areas gradually increases with the increase of the local pattern line width of the pattern in the several sub-pattern areas.
[0013] Furthermore, the first sub-pattern area corresponds to the first edge segment segmentation step size L. min The third sub-pattern area corresponds to the third edge segment segmentation step size L. max The second sub-pattern area corresponds to the second edge segment segmentation step size L2;
[0014] The second edge segment division step length L2 is calculated using the following formula:
[0015] L2=L min +(L max -L min )×(1-e -kW2 );
[0016] Among them, L min The preset minimum edge segment segmentation step size threshold; L max W1 is the preset maximum edge segment segmentation step size threshold; W2 is the line width of the pattern in the second sub-pattern area, and W... th <W2<W1,W th W1 is half the exposure wavelength of the lithography machine; W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change of local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, used to indicate that the intensity of the optical proximity effect decreases exponentially with increasing pattern linewidth.
[0017] Furthermore, each edge segment in the first sub-pattern area is corrected for optical proximity effect using a photoresist model; each edge segment in the third sub-pattern area is corrected for optical proximity effect using a pure optical model; the photoresist model includes optical parameters and photoresist parameters, and the pure optical model includes optical parameters.
[0018] Furthermore, the optical parameters include at least one of the following: light source wavelength, numerical aperture, illumination coherence factor, illumination intensity, lens aberration coefficient, light source depth of focus, light focusing plane position, and optical signal gradient; the photoresist parameters include at least one of the following: acid-base concentration in the photoresist, acid-base diffusion length and acid-base reaction rate, and development time.
[0019] Furthermore, each edge segment in the second sub-pattern area is corrected for optical proximity effect using a hybrid model; the hybrid model exhibits a smooth transition trend from the photoresist model to the pure optical model as the local pattern linewidth in the second sub-pattern area increases.
[0020] Furthermore, the calculation formula for the hybrid model is as follows:
[0021] ΔB(W2,x)=e -kW2 ΔT1(x)+(1-e -kW2 )ΔT2(x);
[0022] Where ΔB(W2,x) is the hybrid model that smoothly transitions from the photoresist model to the pure optical model; x is the endpoint position of the edge line segment in the second sub-pattern region; ΔT1(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the photoresist model; ΔT2(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the pure optical model; W2 is the linewidth of the pattern in the second sub-pattern region, and W th <W2<W1,W th W1 is half the exposure wavelength of the lithography machine; W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change of local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, used to indicate that the intensity of the optical proximity effect decreases exponentially with increasing pattern linewidth.
[0023] Secondly, this application also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor is used to implement the optical proximity effect correction method steps described above when executing the program stored in the memory.
[0024] Thirdly, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the optical proximity effect correction method steps of the optical proximity effect correction model as described above.
[0025] Compared with the prior art, the technical solution provided in this application has at least one of the following beneficial effects:
[0026] As described above, the optical proximity effect correction method and computer-readable storage medium provided in this application include: dividing the target layer in the initial mask into regions according to the local pattern linewidth of different regions to obtain several sub-pattern regions with different local pattern linewidths; segmenting the patterns in each sub-pattern region by edge segments, with different edge segmentation step sizes for different sub-pattern regions; and performing optical proximity effect correction on each edge segment obtained after segmenting the patterns in each sub-pattern region by edge segments, with different optical proximity effect models used for different sub-pattern regions.
[0027] In this application, it is first proposed to divide the target layer in the initial mask into regions according to the local pattern line width of different areas. That is, it proposes to divide the region according to different local pattern line widths. An unexpected effect is that it shows that there is a correlation between the intensity of the optical proximity effect of the pattern and the local line width. For example, the intensity of the optical proximity effect of the pattern will weaken as the local line width increases. Thus, a new optical proximity correction region division method is proposed. Then, for the local linewidth of different sub-pattern areas, a segmentation method with a step size corresponding to the local linewidth and different edge segmentation steps for different sub-pattern areas was set. Unexpected results were obtained: based on the different intensities of optical proximity effect in different sub-pattern areas, segmentation segments with different step sizes and different optical proximity effect correction models were set. In this way, by setting short step-size segmentation segments (i.e., dense segmentation points) in sub-pattern areas with high-intensity optical proximity effect and using a more refined correction model, the correction accuracy of sub-pattern areas with high-intensity optical proximity effect can be guaranteed; while by setting long step-size segmentation segments (i.e., sparse segmentation points) in sub-pattern areas with low-intensity optical proximity effect and using a coarse correction model, the correction time of sub-pattern areas with low-intensity optical proximity effect can be shortened, and the overall correction time of optical proximity effect can be reduced. Attached Figure Description
[0028] The accompanying drawings provide a more in-depth understanding of embodiments of this application and are incorporated herein by reference as a whole. These drawings and descriptions are used to illustrate the principles of some embodiments. It should be noted that all drawings are schematic diagrams and are for illustrative and drawing convenience, and relative sizes and proportions have been adjusted. The same symbols represent corresponding or similar features in different embodiments.
[0029] Figure 1 This is a flowchart illustrating the optical proximity effect correction method in the embodiments of this application.
[0030] Figure 2 This is an example diagram of a target layer in an embodiment of this application.
[0031] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation
[0032] To make the technical solutions and advantages of the embodiments of this application clearer, the technical solutions of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Although exemplary implementation methods of this application are shown in the accompanying drawings, it should be understood that this application can be implemented in various forms and should not be limited to the implementation methods described herein. Rather, these implementation methods are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.
[0033] In the embodiments of this application, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be noted that the technical solutions described in the embodiments of this application can be arbitrarily combined without conflict.
[0034] As mentioned above, in integrated circuit manufacturing, as technology nodes shrink, optical proximity correction (OPC) becomes increasingly important. Since the OPC model is derived mathematically by fitting multiple physical and chemical phenomena involved in the interaction between light and materials during photolithography, traditional OPC models suffer from high complexity and long correction times. Furthermore, as mask designs become more complex, the time spent on OPC increases significantly. Excessive OPC correction time inevitably impacts product progress and hinders business development. Therefore, improving OPC correction efficiency is of paramount importance.
[0035] To overcome the aforementioned shortcomings of online technologies, this application provides an optical proximity effect correction method and a computer-readable storage medium, and proposes a new edge segmentation method to simplify the optical proximity effect correction process and reduce the total correction time for the optical proximity effect.
[0036] The optical proximity effect correction method and computer-readable storage medium of this application will be further described below with reference to the accompanying drawings and embodiments.
[0037] Please refer to Figure 1 The illustration shown is a flowchart of an optical proximity effect correction method according to an embodiment of this application. Figure 1 As shown, the optical proximity effect correction method may include at least the following steps:
[0038] Step S101: Divide the target layer in the initial mask into regions according to the local pattern line width of different areas to obtain several sub-pattern areas with different local pattern line widths.
[0039] Step S102: The patterns in each of the sub-pattern areas are segmented by edge lines, and the segmentation step lengths for the edge lines corresponding to different sub-pattern areas are different.
[0040] Step S103: After dividing the pattern in each of the sub-pattern areas into edge segments, optical proximity effect correction is performed on each edge segment, and the optical proximity effect model used for different sub-pattern areas is different.
[0041] In step S101 above, an initial mask can be provided first; the initial mask includes multiple layers, each layer including multiple main graphics, and the line widths of different main graphics can be different; for example, in this embodiment of the application, the layer to be processed is referred to as the target layer; such as Figure 2 As shown, the target layer in this embodiment is preferably a metal layer; the main graphic in the metal layer is a strip pattern. As the technology nodes become smaller, the positional relationship of multiple main graphics in the metal layer becomes more and more complex, resulting in different line widths of patterns in different areas of the metal layer (i.e., the target layer); in order to distinguish them from the line width of a single main graphic, the line width of the pattern located in different areas is called the local pattern line width in this embodiment, and there may be multiple sub-patterns of multiple main graphics in a certain area.
[0042] Research has shown that when the linewidth of a local pattern in a metal layer is less than a certain width threshold (narrow linewidth region), the Optical Proximity Effect (OPE) is most severe and sensitive, requiring the finest edge segmentation step size to ensure correction accuracy. When the local pattern linewidth is extremely large (wide linewidth region), the optical environment tends to be stable, and sufficient accuracy can be guaranteed even with a large edge segmentation step size. Based on this, after determining the target layer, this application can divide the target layer into several sub-pattern regions based on the local pattern linewidths of patterns in different regions of the target layer, thereby obtaining several sub-pattern regions with different local pattern linewidths; for example, the local pattern linewidths of the patterns in the sub-pattern regions can be... Figure 2 The metal layer shown is divided into a first sub-pattern area A, a second sub-pattern area B, and a third sub-pattern area C.
[0043] The pattern in the first sub-pattern area A has a first minimum linewidth, the pattern in the second sub-pattern area B has a second minimum linewidth, and the pattern in the third sub-pattern area C has a third minimum linewidth. Furthermore, the first minimum linewidth is smaller than the second minimum linewidth, and the second minimum linewidth is smaller than the third minimum linewidth; that is, from the first sub-pattern area to the third sub-pattern area C, the linewidth of the local patterns gradually increases. Additionally, the first minimum linewidth of the pattern in the first sub-pattern area A is less than or equal to half the lithography exposure wavelength, meaning that patterns with a linewidth less than or equal to half the lithography exposure wavelength in a certain region of the metal layer are assigned to the first sub-pattern area A.
[0044] Because there is a correlation between the intensity of the optical proximity effect and the local linewidth (or local pattern linewidth), that is, the intensity of the optical proximity effect weakens as the local pattern linewidth increases. Therefore, the first sub-pattern region A is... Figure 2 The narrow linewidth region in the metal layer shown is the sub-pattern region where a high-intensity optical proximity effect occurs; while the third sub-pattern region C is... Figure 2 The wide-line region in the metal layer shown is the sub-pattern region where a low-intensity optical proximity effect occurs; while the second sub-pattern region B is the transition region between the first sub-pattern region A and the third sub-pattern region C.
[0045] Regarding the first sub-pattern area to the third sub-pattern area C mentioned above, the solution proposed in this application is as follows: For the first sub-pattern area A where a high-intensity optical proximity effect occurs, a sufficient number of cutting points are set, short edge segments are set, and a photoresist model is used for fine correction. This ensures that the pattern in the sub-pattern area where a high-intensity optical proximity effect occurs is finely corrected, thus ensuring correction accuracy. For the third sub-pattern area C where a low-intensity optical proximity effect occurs, a small number of (sparse) cutting points are set, long edge segments are set, and a pure optical model is used for coarse correction. This shortens the correction time for the sub-pattern area where a low-intensity optical proximity effect occurs, and ultimately achieves the goal of reducing the total correction time for the optical proximity effect.
[0046] It should be noted that, since multiple sub-patterns of multiple main graphics may exist within a certain area, when determining the local pattern linewidth of the patterns in the first sub-pattern area A, the second sub-pattern area B, and the third sub-pattern area C, it is necessary to determine the minimum linewidth of all sub-patterns contained within each sub-pattern area. Then, based on this minimum linewidth, it is determined whether the sub-pattern area is an area requiring fine-tuning (narrow linewidth area) or an area requiring coarse-tuning (wide linewidth area). For example, if the first minimum linewidth of the pattern in the first sub-pattern area A is defined as W1, then the range of local pattern linewidths in the first sub-pattern area A is: W1 ≤ W th Among them, W th The wavelength is half that of the lithography machine. Let W3 be the third minimum linewidth of the pattern in the third sub-pattern region C. Then, the range of local pattern linewidths in the third sub-pattern region C is: W3 ≥ W1; where W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change in local linewidth. Let W2 be the second minimum linewidth of the pattern in the second sub-pattern region B. Then, the range of local pattern linewidths in the second sub-pattern region A is: W... th <W2<W1。
[0047] In step S102 above, after dividing the target layer into regions, different edge segment division steps can be set for different sub-pattern areas. That is, the line edges of the local patterns in different sub-pattern areas are divided into division points (edge segment division). However, the number of division points set in different sub-pattern areas and the distance length between two adjacent division points (edge segment division steps) are different. Furthermore, the edge segment division steps corresponding to several sub-pattern areas gradually increase as the line width of the local patterns in several sub-pattern areas increases. For example, the edge segment division step set on the edge edge of the pattern contained in the first sub-pattern area A is smaller than the edge segment division step set on the edge edge of the pattern contained in the second sub-pattern area B. The edge segment division step set on the edge edge of the pattern contained in the second sub-pattern area B is smaller than the edge segment division step set on the edge edge of the pattern contained in the third sub-pattern area C.
[0048] In a preferred embodiment, the edge segment division step size corresponding to the first sub-pattern area A can be the first edge segment division step size L. min That is, the edge segment division step size set on the edges of all patterns in the first sub-pattern area A is the same and is the preset minimum edge segment division step size L. min The minimum edge segment division step size L min This is the lower limit of the edge segment segmentation step size under the worst-case optical proximity effect condition. The edge segment segmentation step size corresponding to the third sub-pattern region C can be the third edge segment segmentation step size L. max That is, the edge segment division step lengths set on the edges of all patterns within the third sub-pattern area C are all the same and are the preset maximum edge segment division step length L. max The maximum edge segment division step size L max This is the upper limit of the edge segment division step size under the optimal optical proximity effect condition.
[0049] For the second sub-pattern region B, which serves as a transition zone from the first sub-pattern region A (narrow linewidth region) to the third sub-pattern region C (wide linewidth region), to ensure the continuity of the optical proximity effect correction results, it is not possible to set the entire sub-pattern region to a specific edge segment division step size. Instead, the edge segment division step size corresponding to the local pattern linewidths in the second sub-pattern region B that are close to / adjacent to the line edges of the first sub-pattern region A (narrow linewidth region) is set to the minimum edge segment division step size L. min The edge segment division step size corresponding to the line edge of the third sub-pattern area C (wide line wide area) is set to be close to (but different from) the maximum edge segment division step size L. maxSimilar (but different); therefore, embodiments of this application propose using a continuously varying exponential function to calculate the edge segmentation step length L2 corresponding to the second sub-pattern region B.
[0050] Specifically, the second edge segment division step size L2 is calculated using the following formula:
[0051] L2=L min +(L max -L min )×(1-e -kW2 );
[0052] Among them, L min The preset minimum edge segment segmentation step size threshold; L max W1 is the preset maximum edge segment segmentation step size threshold; W2 is the line width of the pattern in the second sub-pattern area, and W... th <W2<W1,W th W1 is half the exposure wavelength of the lithography machine; W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change of local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, used to indicate that the intensity of the optical proximity effect decreases exponentially with increasing pattern linewidth.
[0053] Based on the calculation formula of the second edge segment division step length L2 provided in the embodiments of this application, it can be seen that the second edge segment division step length L2 can be set on the line edge of different local patterns in the second sub-pattern area B in the embodiments of this application. That is, the value of L2 is a continuously changing range and not a fixed value, so as to ensure the continuity of the optical proximity effect correction results from the first sub-pattern area A (narrow line width area) to the third sub-pattern area C (wide line width area).
[0054] In step S103 above, after segmenting the patterns in each of the sub-pattern areas (e.g., A~C) using the edge segments, optical proximity correction can be performed on each obtained edge segment. Since the target layer in this embodiment is divided into regions based on different local pattern linewidths, the first sub-pattern area A (narrow linewidth region) requiring high-precision correction can be corrected using a photoresist model that comprehensively characterizes the influencing factors during the lithography process. Conversely, the third sub-pattern area C (wide linewidth region), which does not require high-precision correction, is corrected using a pure optical model that only characterizes the optical properties of the lithography machine. This avoids the problem of excessively long correction times caused by using only one optical proximity correction model (usually a photoresist model) for all patterns in the target layer. Specifically, the photoresist model may include optical parameters and photoresist parameters, and the pure optical model may specifically include optical parameters. The optical parameters may be, for example, at least one of the following: light source wavelength, numerical aperture, illumination coherence factor, illumination intensity, lens aberration coefficient, light source depth of focus, light focusing plane position, and optical signal gradient; the photoresist parameters may be, for example, at least one of the following: acid-base concentration in the photoresist, acid-base diffusion length and acid-base reaction rate, and development time.
[0055] Similarly, to ensure the continuity of the optical proximity effect correction results, the pattern in the second sub-pattern region B in this embodiment cannot be directly corrected using the photoresist model or the pure optical model. Instead, a hybrid model composed of the photoresist model and the pure optical model, whose weights change with the local pattern linewidth, is used for optical proximity effect correction. Furthermore, the hybrid model exhibits a smooth transition from the photoresist model to the pure optical model as the local pattern linewidth in the second sub-pattern region B increases.
[0056] For example, this application provides a calculation formula for a hybrid model, which can specifically be:
[0057] ΔB(W2,x)=e -kW2 ΔT1(x)+(1-e -kW2 )ΔT2(x).
[0058] Where ΔB(W2,x) is the hybrid model that smoothly transitions from the photoresist model to the pure optical model; x is the endpoint position of the edge line segment in the second sub-pattern region; ΔT1(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the photoresist model; ΔT2(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the pure optical model; W2 is the linewidth of the pattern in the second sub-pattern region, and W th <W2<W1,W this 1 / 2 of the exposure wavelength of the lithography machine, W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the variation of the local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, which is used to indicate that the intensity of the optical proximity effect decays exponentially as the linewidth of the pattern increases.
[0059] In combination with the above formula, for the continuously varying linewidth W of the pattern in the second sub-pattern region B th (W2<W<W1), in the embodiment of the present application, for the line edge corresponding to the position close to the first sub-pattern region A in terms of the linewidth value, a hybrid model with a large weight value of the photoresist model and a small weight value of the pure optical model is used for correction; and for the line edge corresponding to the position close to the third sub-pattern region C, a hybrid model with a small weight value of the photoresist model and a large weight value of the pure optical model is used for correction. In this way, the weight of the photoresist model in the hybrid model adopted in the second sub-pattern region B gradually decreases as the local pattern linewidth increases, so that the correction time of part of the patterns in the second sub-pattern region B can also be shortened by changing the weight, that is, the total correction time of the optical proximity effect is further reduced.
[0060] In summary, the optical proximity effect correction method and the computer-readable storage medium provided by the present application include: performing region division on the target layer in the initial mask according to the local pattern linewidth of different regions, so as to obtain a plurality of sub-pattern regions with different local pattern linewidths; performing edge segment segmentation on the patterns in each of the sub-pattern regions, and the edge segment segmentation step sizes corresponding to different sub-pattern regions are different; performing optical proximity effect correction on each edge segment obtained after performing the edge segment segmentation on the patterns in each of the sub-pattern regions, and the optical proximity effect models adopted by different sub-pattern regions are different.
[0061] In this application, it is first proposed to divide the target layer in the initial mask into regions according to the local pattern line width of different areas. That is, it proposes to divide the region according to different local pattern line widths. An unexpected effect is that it shows that there is a correlation between the intensity of the optical proximity effect of the pattern and the local line width. For example, the intensity of the optical proximity effect of the pattern will weaken as the local line width increases. Thus, a new optical proximity correction region division method is proposed. Then, for the local linewidth of different sub-pattern areas, a segmentation method with a step size corresponding to the local linewidth and different edge segmentation steps for different sub-pattern areas was set. Unexpected results were obtained: based on the different intensities of optical proximity effect in different sub-pattern areas, segmentation segments with different step sizes and different optical proximity effect correction models were set. In this way, by setting short step-size segmentation segments (i.e., dense segmentation points) in sub-pattern areas with high-intensity optical proximity effect and using a more refined correction model, the correction accuracy of sub-pattern areas with high-intensity optical proximity effect can be guaranteed; while by setting long step-size segmentation segments (i.e., sparse segmentation points) in sub-pattern areas with low-intensity optical proximity effect and using a coarse correction model, the correction time of sub-pattern areas with low-intensity optical proximity effect can be shortened, and the overall correction time of optical proximity effect can be reduced.
[0062] This application also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory communicate with each other through the communication bus. The memory is used to store computer programs. When the processor executes the program stored in the memory, it implements an optical proximity effect correction method provided in this application.
[0063] In addition, other implementations of the OPC modeling method implemented by the processor executing the program stored in the memory are the same as those mentioned in the aforementioned method embodiment section, and will not be repeated here.
[0064] The communication bus mentioned in the control terminal above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.
[0065] The communication interface is used for communication between the aforementioned electronic devices and other devices.
[0066] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.
[0067] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.
[0068] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores instructions that, when executed on a computer, cause the computer to perform an optical proximity effect correction method as described in any of the above embodiments.
[0069] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).
[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0071] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, electronic devices, and computer-readable storage media are basically similar to the method embodiments, and therefore the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.
[0072] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.
Claims
1. A method for correcting the optical proximity effect, characterized in that, include: Based on the local pattern line width of different regions, the target layer in the initial mask is divided into regions to obtain several sub-pattern regions with different local pattern line widths. The patterns in each of the sub-pattern areas are segmented by edge lines, and the segmentation step size for the edge lines corresponding to different sub-pattern areas is different; Optical proximity effect correction is performed on each edge segment obtained after dividing the pattern in each of the sub-pattern regions by the edge segment, and the optical proximity effect model used for different sub-pattern regions is different.
2. The optical proximity effect correction method as described in claim 1, characterized in that, The sub-pattern area includes a first sub-pattern area, a second sub-pattern area, and a third sub-pattern area; the pattern in the first sub-pattern area has a first minimum line width, the pattern in the second sub-pattern area has a second minimum line width, and the pattern in the third sub-pattern area has a third minimum line width; the first minimum line width is smaller than the second minimum line width, and the second minimum line width is smaller than the third minimum line width.
3. The optical proximity effect correction method as described in claim 2, characterized in that, The first minimum linewidth is less than or equal to half of the lithography machine exposure wavelength.
4. The optical proximity effect correction method as described in claim 1, characterized in that, The step length of the edge line segment corresponding to the several sub-pattern areas gradually increases as the local pattern line width of the pattern in the several sub-pattern areas increases.
5. The optical proximity effect correction method as described in claim 3, characterized in that, The first sub-pattern area corresponds to the first edge segment segmentation step size L min The third sub-pattern area corresponds to the third edge segment segmentation step size L. max The second sub-pattern area corresponds to the second edge segment segmentation step size L2; The second edge segment division step length L2 is calculated using the following formula: L2=L min +(L) max -L min )×(1-e -kW2 ); Among them, L min The preset minimum edge segment segmentation step size threshold; L max W1 is the preset maximum edge segment segmentation step size threshold; W2 is the line width of the pattern in the second sub-pattern area, and W... th <W2<W1,W th W1 is half the exposure wavelength of the lithography machine; W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change of local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, used to indicate that the intensity of the optical proximity effect decreases exponentially with increasing pattern linewidth.
6. The optical proximity effect correction method as described in claim 2, characterized in that, The edge segments in the first sub-pattern area are corrected for optical proximity effect using a photoresist model; the edge segments in the third sub-pattern area are corrected for optical proximity effect using a pure optical model; the photoresist model includes optical parameters and photoresist parameters, and the pure optical model includes optical parameters.
7. The optical proximity effect correction method as described in claim 6, characterized in that, The optical parameters include at least one of the following: light source wavelength, numerical aperture, illumination coherence factor, illumination intensity, lens aberration coefficient, light source depth of focus, light focusing plane position, and optical signal gradient; the photoresist parameters include at least one of the following: acid-base concentration in the photoresist, acid-base diffusion length and acid-base reaction rate, and development time.
8. The optical proximity effect correction method as described in claim 6 or 7, characterized in that, The edge segments in the second sub-pattern area are corrected for optical proximity effect using a hybrid model; the hybrid model shows a smooth transition from the photoresist model to the pure optical model as the local pattern linewidth in the second sub-pattern area increases.
9. The optical proximity effect correction method as described in claim 8, characterized in that, The calculation formula for the hybrid model is as follows: ΔB(W2,x)=e -kW2 ΔT1(x)+(1-e -kW2 )ΔT2(x); Where ΔB(W2,x) is the hybrid model that smoothly transitions from the photoresist model to the pure optical model; x is the endpoint position of the edge line segment in the second sub-pattern region; ΔT1(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the photoresist model; ΔT2(x) is the correction offset corresponding to an edge line segment in the second sub-pattern region calculated using the pure optical model; W2 is the linewidth of the pattern in the second sub-pattern region, and W th <W2<W1,W th W1 is half the exposure wavelength of the lithography machine; W1 is the minimum linewidth at which the optical proximity effect of the pattern does not change with the change of local linewidth; k is the attenuation constant, which is related to the optical sensitivity of the lithography process, and the value of k ranges from 0.015 to 0.025; e −kw2 is the attenuation factor, used to indicate that the intensity of the optical proximity effect decreases exponentially with increasing pattern linewidth.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the optical proximity effect correction method as described in any one of claims 1 to 9.