Optical proximity effect correction method, device, medium and program product based on multiple lithography models

Abstract

The present invention provides an optical proximity effect correction method, device, medium and program product based on multiple lithography models, the method comprising: judging whether there are differences in different regions of the front-layer thin film stack according to the analysis results of the current lithography conditions; evaluating the influence of the differences on the imaging of the current lithography pattern, configuring one or more wafers according to the evaluation results and exposing them respectively to sample modeling data; using the modeling data to calibrate the lithography model respectively; before performing optical proximity correction, classifying and marking the graphics of the input layout according to the graphics of different thin film stack regions of the front layer and different types of graphics; in the process of performing optical proximity correction, respectively calling the corresponding lithography model or sub-lithography model to simulate and correct different types of graphics. The present invention greatly improves the lithography accuracy of each part of the graphics and greatly improves the optical proximity correction effect.

Description

Technical Field

[0001] The present invention relates to the technical field of optical proximity effect correction, and in particular to an optical proximity effect correction method, device, medium and program product based on multiple lithography models. Background Art

[0002] As the complexity of chip design increases, the graphic design on a layout varies greatly in different areas, including the size of the graphic, the density of the graphic, and the manufacturing accuracy requirements of the graphic. For example, the static storage area and the logic circuit area on the logic chip, the storage array area and the peripheral circuit area of ​​the memory chip, etc. Since they are exposed simultaneously on the same mask, the existing optical proximity correction technology will use a lithography model to correct the entire mask. However, due to the influence of the complexity of the graphics and the differences in the thin film stacks in different areas of the front layer caused by the process, it is actually difficult to use a lithography model to accurately correct all the graphics on the mask.

[0003] At present, the commonly used method is to select the model to focus on the calibration of the more important areas on the layout, and extract the error rules of other areas by analyzing the differences between the actual measured values ​​and the model predicted values. The target value model deviation compensation is performed on the graphics of this part of the area in advance, and then the entire layout is corrected based on the model. Finally, the corrected layout can obtain a more accurate lithography target graphic after lithography. The advantage of this method is that a model can be used to complete a more accurate optical proximity correction for the entire complex lithography layout. However, this method also has the following defects. When the target value pre-compensation is performed on the area with large lithography model simulation errors, the extraction of the compensation rules is more complicated and the accuracy is not high, which ultimately leads to poor efficiency and accuracy of the entire optical proximity effect correction work. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an optical proximity effect correction method, device, medium and program product based on multiple lithography models, so as to solve the technical problems of poor working efficiency and accuracy of the existing optical proximity effect correction method.

[0005] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides an optical proximity effect correction method based on multiple lithography models, including: judging whether there are differences in different areas of the front-layer thin film stack according to the analysis results of the current lithography conditions; evaluating the impact of the differences on the imaging of the current layer of lithography graphics, configuring one or more wafers according to the evaluation results and exposing them separately to sample modeling data; using the modeling data to perform lithography model calibration separately, which includes: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, setting data weights separately and establishing corresponding sub-lithography models for each type of modeling data; before performing optical proximity correction, classifying and marking the graphics of the input layout according to the graphics of different front-layer thin film stack areas and different types of graphics; during the optical proximity correction process, calling the corresponding lithography models or sub-lithography models separately to simulate and correct graphics of different categories.

[0006] In some embodiments of the first aspect of the present invention, one or more wafers are configured according to the evaluation results and exposed separately to sample modeling data, and the process includes: if the differences in different areas of the previous thin film stack affect the imaging of the current layer of lithography graphics, wafers with different thin film stacks are configured and one of these wafers is selected as an anchor wafer according to the importance of the graphic area, and a test mask is used to expose the anchor wafer to determine the optimal exposure parameters, and all wafers are exposed and sampled under the same conditions according to the optimal exposure parameters using a test mask to sample modeling data.

[0007] In some embodiments of the first aspect of the present invention, one or more wafers are configured according to the evaluation results and are exposed separately to sample modeling data, and the process also includes: if the differences in different areas of the previous thin film stack have no effect on the imaging of the current layer's lithography pattern, only a wafer with one thin film stack is configured, and a test mask is used to expose and sample on the configured wafer to sample modeling data.

[0008] In some embodiments of the first aspect of the present invention, during the optical proximity correction process, the corresponding lithography models or sub-lithography models are respectively called to simulate and correct different types of graphics, which includes: entering an optical proximity correction loop; in each loop, judging the type of graphic mark in each minimum simulation unit; if there is only one graphic mark, calling the lithography model or sub-lithography model corresponding to the graphic mark to perform contour simulation and correction; if it includes two or more mark graphics, calling the lithography models or sub-lithography models corresponding to various mark graphics to perform contour simulation on the entire simulation unit, and correcting each graphic part; when each graphic simulation contour converges to the target value, the correction loop ends, and the final corrected layout is output.

[0009] In some embodiments of the first aspect of the present invention, the method of judging whether there are differences in different regions of the front thin film stack based on the analysis results of the current lithography conditions includes any one or more combinations of the following: measuring the photoresist thickness of the front thin film stack in different regions, and then analyzing whether there are thickness differences of the front thin film stack; evaluating the light intensity distribution difference of the front thin film stack in different regions through imaging simulation analysis, and then analyzing whether there are differences in the front thin film stack in different regions; measuring and analyzing the optical constants of the front thin film stack in different regions, and then analyzing whether there are differences in the front thin film layer in different regions; the optical constants include refractive index, extinction coefficient, optical band gap, and dispersion model parameters.

[0010] In some embodiments of the first aspect of the present invention, the modeling data includes: critical dimension data, defect detection data, process parameters, virtual measurement data, Radon transform data; the photolithography model includes: optical propagation model, photoresist reaction kinetics model, photoresist exposure model, photoresist development model.

[0011] To achieve the above-mentioned purpose and other related purposes, the second aspect of the present invention provides an optical proximity effect correction device based on multiple lithography models, including: a data acquisition module, used to determine whether there are differences in different areas of the front-layer thin film stack according to the analysis results of the current lithography conditions; evaluate the impact of the differences on the imaging of the current layer of lithography graphics, configure one or more wafers according to the evaluation results and expose them separately to sample modeling data; a model calibration module, used to use the modeling data to perform lithography model calibration separately, which includes: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, then set the data weights separately and establish corresponding sub-lithography models for each type of modeling data; a graphic correction module, used to classify and mark the graphics of the input layout according to the graphics of different thin film stack areas of the front layer and different types of graphics before performing optical proximity correction; during the optical proximity correction process, call the corresponding lithography model or sub-lithography model to simulate and correct different categories of graphics.

[0012] To achieve the above-mentioned object and other related objects, the third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the optical proximity effect correction method based on multiple lithography models is implemented.

[0013] To achieve the above-mentioned purpose and other related purposes, the fourth aspect of the present invention provides a computer program product, which includes a computer program code. When the computer program code runs on a computer, the computer implements the optical proximity effect correction method based on multiple lithography models.

[0014] To achieve the above-mentioned purpose and other related purposes, the fifth aspect of the present invention provides a computer device, including a memory, a processor and a computer program stored in the memory; the processor executes the computer program to implement the optical proximity effect correction method based on multiple lithography models.

[0015] As described above, the optical proximity effect correction method, device, medium and program product based on multiple lithography models of the present invention have the following beneficial effects: the present invention establishes and uses multiple different lithography models to respectively correct graphics of different types and different areas on a complex lithography layer, thereby greatly improving the lithography accuracy of each part of the graphics and greatly improving the optical proximity correction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic flow chart of an optical proximity effect correction method based on multiple lithography models according to an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of a process of using multiple lithography models to perform optical proximity effect correction on a complex lithography layer in one embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of a process of performing optical proximity correction on an input layout in one embodiment of the present invention.

[0019] Figure 4 Shown is a schematic diagram of graphic classification and labeling of an input layout in one embodiment of the present invention.

[0020] Figure 5 It is a schematic diagram showing the use of multiple lithography models to modify an input layout in one embodiment of the present invention.

[0021] Figure 6 It is a schematic structural diagram of an optical proximity effect correction device based on multiple lithography models in one embodiment of the present invention.

[0022] Figure 7 Shown is a schematic diagram of the structure of a computer device in one embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] Before further describing the present invention in detail, the nouns and terms involved in the embodiments of the present invention are explained. The nouns and terms involved in the embodiments of the present invention are applicable to the following interpretations:

[0025] <1> Optical proximity correction: Pre-compensation of the photomask pattern to make the silicon wafer image meet the design specifications as closely as possible.

[0026] <2> The photolithography model is a mathematical model used to describe the physical and chemical phenomena in the photolithography process. It is used to predict and simulate the imaging results of light on the photoresist under different conditions, and to pre-compensate the graphics on the mask accordingly so that the final imaging on the silicon wafer is as close as possible to the design specifications.

[0027] The present invention provides an optical proximity effect correction method, device, medium and program product based on multiple lithography models. By establishing and using multiple different lithography models to respectively correct different types and different areas of graphics on a complex lithography layer, the lithography accuracy of each part of the graphics is greatly improved, and the optical proximity correction effect is greatly improved. Hereinafter, the technical solution of the present invention will be explained in detail in conjunction with specific embodiments.

[0028] Figure 1 The flowchart of a method for correcting an optical proximity effect based on multiple lithography models in an embodiment of the present invention is shown. The method for correcting an optical proximity effect in this embodiment mainly includes the following steps.

[0029] Step S11: determine whether there are differences in the front-layer thin film stack in different areas based on the analysis results of the current lithography conditions; evaluate the impact of the differences on the imaging of the current lithography pattern, configure one or more wafers based on the evaluation results and expose them separately to sample modeling data.

[0030] In an embodiment of the present invention, the process of configuring one or more wafers according to the evaluation results and performing exposure respectively to sample modeling data includes:

[0031] If the differences in different areas of the previous thin film stack affect the imaging of the current layer's photolithography graphics, wafers with different thin film stacks are configured and one of these wafers is selected as an anchor wafer according to the importance of the graphic area. A test mask is used to expose the anchor wafer to determine the optimal exposure parameters (such as light source intensity, exposure time, focal length, depth of focus and other parameters). A test mask is used to expose and sample all wafers under the same conditions according to the optimal exposure parameters, and modeling data is sampled based on this.

[0032] If the differences in the previous thin film stack in different areas have no effect on the imaging of the current layer's photolithography pattern, only a wafer with one thin film stack is configured, and exposure and sampling are performed on the configured wafer using a test mask to sample modeling data.

[0033] It should be understood that the modeling data collected after exposure and sampling on the wafer is used to establish the quality control and process optimization model in the semiconductor manufacturing process. These modeling data include, but are not limited to: critical dimension data, defect detection data, process parameters, virtual measurement data, Radon transform data, etc. Critical dimension data (CD) is the minimum feature size in a semiconductor device and is an important parameter for measuring the accuracy of the circuit pattern on the wafer; defect detection data refers to the data used to detect whether there are defects (such as particles, scratches, cracks, etc.) on the wafer during the semiconductor manufacturing process; process parameters refer to the parameters controlled in each step of semiconductor manufacturing, such as temperature, pressure, time, etc.; virtual measurement data refers to data obtained through simulation or calculation, which is used to predict the results of actual physical measurements; Radon transform data is a mathematical transformation used to extract straight line features from an image, and the defect pattern on the wafer can be identified through Radon transform.

[0034] Combination Figure 2 The flowchart of using multiple lithography models to correct the optical proximity effect of complex lithography layers is further explained. If the differences in different regions of the previous thin film stack affect the imaging of the current lithography pattern, the wafers configured with different thin film stacks are wafer 1, wafer 2, ... wafer N, and the important thin film stack is used as the anchor wafer. The best exposure parameters (such as exposure energy and depth of focus) are selected, and all wafers are exposed under the same conditions using a test mask, and sampling is performed. The modeling data obtained include wafer 1 modeling data, wafer 2 modeling data, ... wafer N modeling data.

[0035] In the embodiment of the present invention, judging whether the front-layer thin film stack has differences in different regions according to the analysis result of the current photolithography conditions can be achieved by any of the following methods.

[0036] Implementation method 1) By measuring the photoresist thickness of the front film stack in different areas, analyze whether there is a thickness difference in the front film stack. Specifically, the photoresist thickness of the front film stack in different areas can be measured by any of the following methods: (a) Based on non-contact optical measurement method, this method is based on non-contact optical measurement of refractive index. The visual thickness of the film is obtained by adjusting the fine focusing screw of the microscope, and then the refractive index of the photoresist to the microscope light is determined by experiment. The product of the two is the actual thickness of the film. (b) Spectral reflection modeling measurement method, which measures the thickness of the photoresist through accurate spectral reflection modeling. (c) Photoresist film thickness measurement method based on monochromatic light interference, which uses the transparency of the photoresist and its sensitivity to short-wave light, and measures the film thickness through the interference fringes formed by the reflection of the light beam at the upper and lower interfaces of the photoresist film. The film thickness of the photoresist can be accurately measured by automatic counting of interference fringes and the principle of relative light intensity. (d) X-ray grazing method, using X-ray diffractometer to measure the thickness of nanofilms.

[0037] Implementation method 2) Use imaging simulation analysis to evaluate the difference in light intensity distribution of the front thin film stack in different areas, and then analyze whether there are differences in the front thin film stack in different areas. It should be understood that when light passes through the film layer, it will be reflected and transmitted at the interface, and these light waves will eventually affect the light intensity distribution in the photoresist. By extracting the light intensity values ​​of specific rows or columns through the simulation results, the uniformity of the light intensity distribution can be analyzed. By comparing the light intensity analysis of different areas, it can be analyzed whether there are thickness differences in the front thin film stack.

[0038] Implementation method 3) By measuring and analyzing the optical constants of different regions of the front film stack, it is analyzed whether there are differences in the front film layers in different regions; the optical constants include but are not limited to refractive index, extinction coefficient, optical band gap, dispersion model parameters, etc. The refractive index is a function of the wavelength λ of the light wave, which describes the ratio of the propagation speed of light in the material to the propagation speed in a vacuum; the extinction coefficient is also a function of the wavelength λ of the light wave, which describes the degree to which light is absorbed when propagating in the material; the optical band gap is an important parameter that describes the light absorption characteristics of the material; the dispersion model parameters are used to describe the relationship between the refractive index and the extinction coefficient as the wavelength changes. By measuring these optical constants and analyzing their changes in different regions, it is possible to evaluate whether there are differences in the front film stack in different regions.

[0039] Furthermore, the differences in the front film stack in different areas may have an impact on the imaging of the current photolithography pattern, including but not limited to: when there are problems such as light intensity changes, insufficient focus depth, high mask error factor, poor development, narrow photoresist pattern limit, and photoresist residue, it can be inferred that the differences in the front film stack have an impact on the imaging of the current photolithography image. For example, in the case of insufficient focus depth, if the photolithography process does not have enough focus depth, holes will be missing in a certain area when there is a little ups and downs on the silicon wafer surface, indicating that the differences in the front film stack affect the imaging quality of the photolithography image. In the case of poor development, due to poor development or development washing, the dissolved and partially dissolved photoresist residues cannot be effectively removed from the silicon wafer surface. This type of defect will first occur at the edge of the silicon wafer, which is related to the differences in the front film stack and affects the imaging of the photolithography image. In the case of photoresist residue, before the photolithography plane is adjusted, the photolithography process tolerance in some areas is small, resulting in photoresist residue. The photoresist residue problem can be significantly improved by adjusting the position of the photolithography plane, which shows that the difference in the previous film stack has an impact on the lithography image imaging.

[0040] Step S12: using the modeling data to perform lithography model calibration respectively, which includes: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, setting data weights respectively and establishing corresponding sub-lithography models for each type of modeling data.

[0041] It should be noted that the photolithography model is used to describe the response of photoresist to light during the photolithography process and the mathematical model of the photoresist pattern transfer process. These models are crucial for optimizing the photolithography process, predicting the photolithography results, and improving the design of photolithography equipment. The photolithography model includes but is not limited to: optical propagation model, photoresist reaction kinetic model, photoresist exposure model, photoresist development model, etc. Among them, the optical propagation model is used to describe the propagation process of light between the mask and the photoresist, including physical phenomena such as light diffraction and interference. The photoresist reaction kinetic model is used to describe the chemical reaction of the photoresist during the exposure process, including the decomposition of the photoinitiator and the breakage of the photoresist molecular chain. The photoresist exposure model is used to describe the energy absorption and photosensitization reaction of the photoresist during the exposure process. The photoresist development model is used to describe the dissolution behavior of the photoresist during the development process, including the diffusion of the developer and the dissolution rate of the photoresist.

[0042] In an embodiment of the present invention, each set of wafer model calibration data is analyzed separately to determine whether different types of modeling data (corresponding to different classification patterns on the layout) can be accurately predicted. If calibration is not possible at the same time, data weights are set separately to establish corresponding sub-lithography models so that different types of patterns on the layout have corresponding models that can be accurately predicted. It should be understood that the sub-lithography model is actually also a lithography model, but because the same lithography model cannot handle all classification patterns on the wafer, it is necessary to model each type of data (corresponding to each type of classification pattern) separately to improve the correction accuracy.

[0043] Combination Figure 2 For example, the wafer 1 model can establish the following sub-lithography models for different types of sampling data: model 1-1, model 1-2, ... model 1-N. Similarly, the wafer 2 model can establish the following wafer sub-models for different types of sampling data: model 2-1, model 2-2, ... model 2-N, and so on. Other wafer models are not listed one by one.

[0044] Step S13: Before performing optical proximity correction, the graphics of the input layout are classified and marked according to the graphics of different thin film stacking areas in the front layer and different types of graphics; during the optical proximity correction process, the corresponding lithography models or sub-lithography models are called to simulate and correct different types of graphics.

[0045] In some examples, step S13 can be divided into Figure 3 The steps shown.

[0046] Step S13a: Classify and mark the graphics of the input layout according to the graphics of different thin film stacking areas of the front layer and different types of graphics.

[0047] It should be understood that the "input layout" refers to the circuit pattern designed on the mask, which will eventually be transferred to the wafer through the photolithography process. The "previous layer different thin film layer area graphics" refers to the superposition area of ​​different material layers (such as metal layers, insulating layers, etc.) formed in the previous manufacturing process. The graphic features of these areas are different and need to be considered separately. "Different types of graphics" refer to graphics of different shapes and features on the layout, such as straight lines, curves, holes, etc. Different types of graphics have different optical properties in the photolithography process and need to be processed separately. Therefore, before performing optical proximity correction, these graphics need to be classified according to certain rules. The purpose is to be able to correct different types of graphics more accurately in the future to ensure the quality of the photolithography process.

[0048] Combination Figure 4Taking the example as an example, the input layout is classified according to the front-layer film stacking area and the graphic type to which it belongs, and marked as classification graphic 1, classification graphic 2, and classification graphic N. Among them, model 1 is used for classification graphic 1, model 2 is used for classification graphic 2, and model N is used for classification graphic N.

[0049] Step S13b: Enter the optical proximity correction loop; in each loop, determine the type of graphic mark in each minimum simulation unit; if there is only one graphic mark, call the lithography model or sub-lithography model corresponding to the graphic mark to perform contour simulation and correction; if it includes two or more mark graphics, call the lithography model or sub-lithography model corresponding to each mark graphic to perform contour simulation on the entire simulation unit, and correct each graphic part.

[0050] Combination Figure 5 To explain, the input layout is divided according to the minimum simulation unit, and the type of graphic mark in each minimum simulation unit is analyzed. For example, there is only one graphic mark in the minimum simulation unit M, namely classification graphic 1, and the corresponding model 1-1 can be called for correction. There are two graphic marks in the minimum simulation unit N, namely classification graphic 2 and classification graphic N. The corresponding models 1-2 and 1-N need to be called respectively. Model 1-2 calculates the entire contour based on the contour correction graphic 2 part, and model 1-N calculates the entire contour based on the contour correction graphic N part.

[0051] Step S13c: When each graphic simulation contour converges to the target value, the correction cycle ends and the final corrected layout is output. It should be understood that the target value referred to here refers to the expected graphic contour in the design, that is, the pattern shape and size that is expected to be achieved on the wafer.

[0052] It should be noted that, in the embodiments of the present invention, words such as "exemplary" or "for example" represent examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the embodiments of the present invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c may represent: a, b, c, ab, ac, bc or abc, where a, b, c may be single or plural.

[0054] Figure 6 is a schematic block diagram of an optical proximity effect correction device based on multiple lithography models provided by an embodiment of the present invention. Figure 6 As shown, the device includes a data acquisition module 601, a model calibration module 602, and a graphic correction module 603.

[0055] The data acquisition module 601 is used to determine whether there are differences in the previous thin film stack in different areas based on the analysis results of the current lithography conditions; evaluate the impact of the differences on the imaging of the current lithography pattern, configure one or more wafers based on the evaluation results and expose them separately to sample modeling data.

[0056] The model calibration module 602 is used to use the modeling data to perform lithography model calibration respectively, which includes: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, setting data weights respectively and establishing corresponding sub-lithography models for each type of modeling data.

[0057] The graphic correction module 603 is used to classify and mark the graphics of the input layout according to the graphics of different thin film stacking areas in the front layer and different types of graphics before performing optical proximity correction; during the optical proximity correction process, the corresponding lithography model or sub-lithography model is called to simulate and correct different types of graphics.

[0058] It should be noted that the implementation principle and process of the optical proximity effect correction device based on multiple lithography models provided in the embodiment of the present invention are similar to the optical proximity effect correction method based on multiple lithography models described above, and will not be repeated here. The specific process of each module executing the above corresponding steps has been described in detail in the above method embodiment, and will not be repeated here for the sake of brevity.

[0059] It should also be understood that the division of modules in the embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention may be integrated into a processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0060] Figure 7 is a schematic block diagram of a computer device provided by an embodiment of the present invention. Figure 7 As shown, the computer device 700 includes: at least one processor 701, a memory 702, at least one network interface 703 and a user interface 705. The various components in the device are coupled together through a bus system 704. It can be understood that the bus system 704 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 704 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, the bus system 704 is not used in the embodiment of the present invention. Figure 7 In the specification, various buses are labeled as bus systems.

[0061] The user interface 705 may include a display, a keyboard, a mouse, a trackball, a click gun, keys, buttons, a touch pad or a touch screen.

[0062] It is understood that the memory 702 can be a volatile memory or a non-volatile memory, and can also include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), which is used as an external cache. By way of exemplary but not limiting explanation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM). The memory described in the embodiments of the present invention is intended to include but is not limited to these and any other suitable categories of memory.

[0063] The memory 702 in the embodiment of the present invention is used to store various types of data to support the operation of the computer device 700. Examples of these data include: any executable program for operating on the computer device 700, such as an operating system 7021 and an application 7022; the operating system 7021 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application 7022 can include various applications, such as a media player (Media Player), a browser (Browser), etc., for implementing various application services. The optical proximity effect correction method based on multiple lithography models provided in the embodiment of the present invention can be included in the application 7022.

[0064] The method disclosed in the above embodiment of the present invention can be applied to the processor 701, or implemented by the processor 701. The processor 701 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit in the processor 701 or the instruction in the form of software. The above processor 701 may be a general processor, a digital signal processor (DSP, Digital Signal Processor), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The processor 701 can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiment of the present invention. The general processor 701 may be a microprocessor or any conventional processor, etc. In combination with the steps of the accessory optimization method provided in the embodiment of the present invention, it can be directly embodied as a hardware decoding processor to execute, or it can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium, which is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0065] In an exemplary embodiment, the computer device 700 may be one or more application specific integrated circuits (ASIC), DSP, programmable logic device (PLD), complex programmable logic device (CPLD) to execute the aforementioned method.

[0066] According to the method provided by the embodiment of the present invention, the present invention also provides a computer program product, the computer program product comprising: a computer program code, when the computer program code is run on a computer, the computer executes Figures 1 to 5An optical proximity effect correction method based on multiple lithography models in any of the illustrated embodiments.

[0067] According to the method provided by an embodiment of the present invention, the present invention also provides a computer-readable storage medium, which stores a program code. When the program code runs on a computer, the computer executes the above method.

[0068] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process, a processor, an object, an executable file, an execution thread, a program and / or a computer running on a processor. By way of illustration, both applications and computing devices running on a computing device can be components. One or more components may reside in a process and / or an execution thread, and a component may be located on a computer and / or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0069] Those skilled in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0070] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0071] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0072] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0073] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0074] In the above embodiments, the functions of each functional unit can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, the process or function according to the embodiment of the present invention is generated in whole or in part. 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 computer-readable storage medium. For example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated. Available media may be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., high-density digital video discs (DVDs), or semiconductor media (e.g., solid state disks (SSDs)).

[0075] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0076] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0077] In summary, the present invention provides an optical proximity effect correction method, device, medium and program product based on multiple lithography models. The present invention establishes and uses multiple different lithography models to respectively correct different types and different areas of graphics on a complex lithography layer, thereby greatly improving the lithography accuracy of each part of the graphics and greatly improving the optical proximity correction effect. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0078] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An optical proximity effect correction method based on multiple lithography models, characterized in that: include: Determine whether the front film stack has differences in different regions based on the analysis results of the current lithography conditions; Evaluate the influence of the difference on the imaging of the current photolithography pattern, configure one or more wafers according to the evaluation results and expose them respectively to sample modeling data; judge whether there are differences in different regions of the front film stack according to the analysis results of the current photolithography conditions, and the judgment method includes any one or more combinations of the following: by measuring the photoresist thickness of the front film stack in different regions, and then analyzing whether there are thickness differences of the front film stack; by evaluating the light intensity distribution difference of the front film stack in different regions through imaging simulation analysis, and then analyzing whether there are differences in the front film stack in different regions; by measuring and analyzing the optical constants of different regions of the front film stack, and then analyzing whether there are differences in the front film layer in different regions; The photolithography model calibration is performed respectively using the modeling data, which includes: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, respectively setting data weights and establishing corresponding sub-photolithography models for each type of modeling data; Before performing optical proximity correction, the graphics of the input layout are classified and marked according to the graphics of different thin film stacking areas in the front layer and different types of graphics; during the optical proximity correction process, the corresponding lithography models or sub-lithography models are called to simulate and correct different types of graphics; the different types of graphics refer to graphics with different shapes and characteristics on the layout.

2. The optical proximity effect correction method based on multiple lithography models according to claim 1, characterized in that: The process of configuring one or more wafers according to the evaluation results and performing exposure respectively to sample modeling data includes: If the differences in different areas of the previous thin film stack affect the imaging of the current layer's lithography graphics, wafers with different thin film stacks are configured and one of these wafers is selected as an anchor wafer according to the importance of the graphic area. A test mask is used to expose the anchor wafer to determine the optimal exposure parameters, and all wafers are exposed and sampled under the same conditions according to the optimal exposure parameters using a test mask to sample modeling data.

3. The optical proximity effect correction method based on multiple lithography models according to claim 1, characterized in that: The process of configuring one or more wafers according to the evaluation results and performing exposure respectively to sample modeling data also includes: If the differences in the previous thin film stack in different areas have no effect on the imaging of the current layer's photolithography pattern, only a wafer with one thin film stack is configured, and exposure and sampling are performed on the configured wafer using a test mask to sample modeling data.

4. The optical proximity effect correction method based on multiple lithography models according to claim 1, characterized in that: In the process of performing optical proximity correction, corresponding lithography models or sub-lithography models are respectively called to simulate and correct different types of graphics, which includes: Entering an optical proximity correction loop; in each loop, determining the type of graphic mark in each minimum simulation unit; If there is only one graphic mark, the lithography model or sub-lithography model corresponding to the graphic mark is called to perform contour simulation and correction; If two or more marking patterns are included, the lithography models or sub-lithography models corresponding to the various marking patterns are respectively called to perform contour simulation on the entire simulation unit, and corrections are made to the respective pattern parts; When each graphic simulation contour converges to the target value, the correction cycle ends and the final corrected layout is output.

5. The optical proximity effect correction method based on multiple lithography models according to claim 1, characterized in that: The optical constants include refractive index, extinction coefficient, optical band gap, and dispersion model parameters.

6. The optical proximity effect correction method based on multiple lithography models according to claim 1, characterized in that: The modeling data includes: key dimension data, defect detection data, process parameters, virtual measurement data, and Radon transformation data; the photolithography model includes: optical propagation model, photoresist reaction kinetics model, photoresist exposure model, and photoresist development model.

7. An optical proximity effect correction device based on multiple lithography models, characterized in that: include: A data acquisition module is used to determine whether the front film stack has differences in different areas based on the analysis results of the current photolithography conditions; Evaluate the influence of the difference on the imaging of the current photolithography pattern, configure one or more wafers according to the evaluation results and expose them respectively to sample modeling data; judge whether there are differences in different regions of the front film stack according to the analysis results of the current photolithography conditions, and the judgment method includes any one or more combinations of the following: by measuring the photoresist thickness of the front film stack in different regions, and then analyzing whether there are thickness differences of the front film stack; by evaluating the light intensity distribution difference of the front film stack in different regions through imaging simulation analysis, and then analyzing whether there are differences in the front film stack in different regions; by measuring and analyzing the optical constants of different regions of the front film stack, and then analyzing whether there are differences in the front film layer in different regions; A model calibration module, used to perform lithography model calibration respectively using the modeling data, comprising: if the model fitting error of different types of modeling data on the same wafer exceeds a preset threshold, setting data weights respectively and establishing corresponding sub-lithography models for each type of modeling data; The graphics correction module is used to classify and mark the graphics of the input layout according to the graphics of different thin film stacking areas in the front layer and different types of graphics before performing optical proximity correction; during the optical proximity correction process, the corresponding lithography model or sub-lithography model is called to simulate and correct different types of graphics; the different types of graphics refer to graphics with different shapes and characteristics on the layout.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the optical proximity effect correction method based on multiple lithography models described in any one of claims 1 to 6 is implemented.

9. A computer program product, characterized in that The computer program product includes computer program codes, and when the computer program codes are run on a computer, the computer is enabled to implement the optical proximity effect correction method based on multiple lithography models as claimed in any one of claims 1 to 6.

10. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the optical proximity effect correction method based on multiple lithography models as claimed in any one of claims 1 to 6.

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