Opportunity to purchase (opc) model construction method and apparatus, computer readable storage medium, and terminal

Abstract

The application discloses an OP model construction method and device, a storage medium and a terminal, wherein the method comprises the following steps: performing optical exposure simulation on a test mask to obtain initial simulation data, screening unit patterns in the initial simulation data based on a first screening condition to obtain initial unit pattern information; obtaining a preliminary machine measurement program established based on the initial unit pattern information, collecting initial actual wafer CD data of a wafer to be measured based on the preliminary machine measurement program, and judging the initial actual wafer CD based on a preset modeling condition to establish an initial OP model; simulating the test mask based on the initial OP model to obtain secondary simulation data, screening unit patterns in the secondary simulation data based on a second screening condition to obtain secondary unit pattern information; and obtaining a final OP model based on the secondary unit pattern information. The intelligent measurement mode is used to optimize the existing artificial participation measurement mode, improve the measurement efficiency and reduce the error caused by human factors.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to an OPC model construction method and related apparatus. Background Technology

[0002] With advancements in semiconductor process technology, the amount of measurement data required for developing OPC models for advanced nodes is gradually increasing. Furthermore, since each specialty process in semiconductor manufacturing is relatively independent, a corresponding independent OPC optimization model must be established for each specialty process to obtain more accurate results, thus requiring even more data from both sides. The conventional OPC model establishment process involves first collecting a large amount of CD-SEM measurement data, and then fitting and optimizing the measurement data to calibrate the established OPC model, ultimately ensuring that the calculation results of the lithography model match the actual experimental results.

[0003] The collection of actual measurement data requires the use of a high-resolution electron microscope. Therefore, daily actual measurement data needs to be collected manually, which is not only time-consuming and labor-intensive, but also prone to errors, thus affecting the accuracy of the final OPC model. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this application is to provide an OPC model construction method and apparatus, computer-readable storage medium and terminal, to solve the problem that the existing OPC model construction requires a lot of human resources, which is not only time-consuming and laborious, but also prone to errors, affecting the accuracy of the established OPC model.

[0005] Firstly, this application provides a method for constructing an OPC model, including:

[0006] The test mask is subjected to optical exposure simulation based on preset light source exposure conditions to obtain preliminary simulation data. The unit patterns in the preliminary simulation data are filtered based on the first screening condition to obtain preliminary unit pattern information. The preset light source exposure conditions include the proposed light source and energy and focal length variation matrix.

[0007] A preliminary instrumentation program is obtained based on the preliminary unit pattern information. Based on the preliminary instrumentation program, preliminary actual wafer CD data of the wafer under test is collected on the instrument under the preset light source exposure conditions. It is determined whether the preliminary actual wafer CD meets the preset modeling conditions. If so, an initial OPC model is established based on the current preliminary actual wafer CD data. The proposed light source in the current preset light source exposure conditions is taken as the target light source, and the optimal focal length and optimal energy in the energy and focal length change matrix of the current preset light source exposure conditions are taken as the target exposure conditions. Otherwise, the current preset light source exposure conditions are adjusted to obtain new preset light source exposure conditions, and the optical exposure simulation of the test mask is performed again based on the new preset light source exposure conditions.

[0008] Under the target light source and the target exposure conditions, the test mask is subjected to optical exposure simulation based on the initial OPC model to obtain re-simulation data, and the unit patterns in the re-simulation data are filtered based on the second filtering condition to obtain re-unit pattern information;

[0009] A re-measurement program based on the re-unit pattern information is obtained. Based on the re-measurement program, the actual wafer CD data of the wafer under test is collected on the measurement machine under the target light source and the target exposure conditions. The final OPC model is established based on the actual wafer CD data.

[0010] The wafer to be tested is any wafer that has been exposed using the test mask.

[0011] In one embodiment of this application, before the step of performing optical exposure simulation on a test mask based on preset light source exposure conditions to obtain preliminary simulation data, and filtering the unit patterns in the preliminary simulation data based on a first filtering condition to obtain preliminary unit pattern information, the method further includes:

[0012] Name each unit pattern on the test mask;

[0013] Both the preliminary unit pattern information and the secondary unit pattern information include the name information of the selected unit patterns.

[0014] In one embodiment of this application, the preset modeling conditions include:

[0015] The image containing the preliminary actual wafer CD data has a resolution greater than a preset resolution threshold, and the image containing the preliminary actual wafer CD data is complete.

[0016] In the preliminary actual wafer CD data, the percentage of the number of unit patterns with linewidth in the first value range to the total number of unit images is greater than a preset percentage threshold.

[0017] The exposure latitude and focus depth obtained from the preliminary actual wafer CD data both meet the preset light source exposure conditions.

[0018] In one embodiment of this application, the first filtering condition includes a target linewidth and a first value range including the target linewidth.

[0019] In one embodiment of this application, the second filtering condition includes a target linewidth and a second value range including the target linewidth, wherein the second value range is smaller than the first value range.

[0020] In one embodiment of this application, both the initial OPC model and the final OPC model are established using EDA software.

[0021] In one embodiment of this application, the proposed light source is obtained by simulation based on the proposed light source information using EDA software.

[0022] Secondly, this application also provides an OPC model building device, including a preliminary unit pattern information acquisition module, an initial OPC model acquisition module, a secondary unit pattern information acquisition module, and a final OPC model building module;

[0023] The preliminary unit pattern information acquisition module is used to perform optical exposure simulation on the test mask based on preset light source exposure conditions to obtain preliminary simulation data, and to filter the unit patterns in the preliminary simulation data based on the first screening condition to obtain preliminary unit pattern information. The preset light source exposure condition includes a proposed light source and an energy and focal length variation matrix.

[0024] The initial OPC model acquisition module is used to acquire a preliminary instrumentation program established based on the preliminary unit pattern information, and to collect preliminary actual wafer CD data of the wafer under test on the instrumentation machine under the preset light source exposure conditions based on the preliminary instrumentation program. It determines whether the preliminary actual wafer CD meets the preset modeling conditions. If so, it establishes an initial OPC model based on the current preliminary actual wafer CD data, and takes the proposed light source in the current preset light source exposure conditions as the target light source, and takes the best focal length and best energy in the energy and focal length change matrix in the current preset light source exposure conditions as the target exposure conditions. Otherwise, it adjusts the current preset light source exposure conditions to obtain new preset light source exposure conditions, and re-performs optical exposure simulation on the test mask based on the new preset light source exposure conditions.

[0025] The re-unit pattern information is used to perform optical exposure simulation on the test mask based on the initial OPC model under the target light source and the target exposure conditions to obtain re-simulation data, and to filter the unit patterns in the re-simulation data based on the second filtering condition to obtain re-unit pattern information.

[0026] The final OPC model building module is used to obtain a re-machine measurement program based on the re-unit pattern information, collect the actual wafer CD data of the wafer under test on the measurement machine under the target light source and the target exposure conditions based on the re-machine measurement program, and build the final OPC model based on the actual wafer CD data.

[0027] The wafer to be tested is any wafer that has been exposed using the test mask.

[0028] Thirdly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the OPC model construction method.

[0029] Fourthly, this application also provides a terminal, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the OPC model construction method.

[0030] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0031] The OPC model construction method provided in this invention involves obtaining preliminary unit pattern information by optically exposing and initially screening a test mask. Then, based on this preliminary unit pattern information, preliminary actual wafer CD data is obtained and screened according to modeling conditions to ensure the coverage of the current design pattern. Finally, the test mask is optically exposed based on the initial OPC model established through modeling condition screening, and the data obtained from the exposure is further refined to make the collected measurement data more representative, achieving the purpose of selecting appropriate data for fitting and calibration, and ensuring the accuracy of the final OPC model. This invention employs an intelligent measurement method that optimizes existing manual measurement methods while improving measurement efficiency and reducing errors caused by human factors. Measurement results are all based on optical model data, which improves model accuracy. The unit patterns in the test mask are named to facilitate subsequent screening of unit pattern information based on screening conditions, achieving intelligent improvement in unit pattern and measurement data collection.

[0032] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 The diagram shown is a flowchart illustrating the OPC model construction method described in this application embodiment.

[0035] Figure 2 The diagram shown is a structural schematic of the OPC model building apparatus described in an embodiment of this application.

[0036] Figure 3 The diagram shown is a structural schematic of the terminal described in an embodiment of this application. Detailed Implementation

[0037] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0038] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0039] The following embodiments of this application provide an OPC model construction method and apparatus, a computer-readable storage medium and a terminal, which solve the problem that the existing OPC model construction requires a lot of human resources, which is not only time-consuming and laborious, but also prone to errors, affecting the accuracy of the established OPC model.

[0040] The following will describe in detail, with reference to the accompanying drawings, the principles and implementation methods of an OPC model construction method and apparatus, a computer-readable storage medium and a terminal of this embodiment, so that those skilled in the art can understand the OPC model construction method and apparatus, the computer-readable storage medium and the terminal of this embodiment without creative effort.

[0041] like Figure 1 As shown in the figure, this embodiment provides an OPC model construction method, which includes the following steps.

[0042] Step S101: Perform optical exposure simulation on the test mask based on preset light source exposure conditions to obtain preliminary simulation data, and filter the unit patterns in the preliminary simulation data based on the first screening condition to obtain preliminary unit pattern information.

[0043] Specifically, the test mask to be tested is determined. The test mask is typically pre-set based on requirements and features multiple and various types of unit patterns (gauges), each with corresponding positional information. Simultaneously, preset light source exposure conditions are acquired, including a matrix of proposed light source, energy, and focal length variations. EDA (Electronic Design Automation) software can simulate the proposed light source and its energy and focal length variation matrices based on the preset exposure conditions.

[0044] Optical exposure simulations were performed on the test mask using a simulated light source under energy and focal length variation matrix exposure conditions to obtain simulation data. All acquired simulation data were collected as preliminary simulation data. The preliminary simulation data specifically includes the position information of each unit image in the test mask and the linewidth value of each unit image (i.e., wafer CD data value).

[0045] A first filtering condition is pre-defined, including the target linewidth and a first value range encompassing the target linewidth. This first value range is typically set based on the target linewidth; for example, the left endpoint of the first value range could be the target linewidth minus a preset value, and the right endpoint could be the target linewidth plus the preset value. Then, the preliminary simulation data is filtered based on this first filtering condition to identify all unit image information (specifically, the positional information of the unit images) whose linewidths satisfy the first value range. The selected unit image information is then aggregated into preliminary unit pattern information. Typically, the first value range can be set based on the number of selected unit images being approximately 10% of the total number of unit images in the test mask. This setting ensures the accuracy of the preliminary simulation data while reducing the amount of data processing.

[0046] The first screening condition can be implemented in the form of a first intelligent measurement script, that is, the first intelligent measurement script extracts data from the preliminary simulation data in order to screen out all unit pattern information that meets the first value range from the preliminary simulation data.

[0047] Step S102: Obtain the preliminary instrument measurement program established based on the preliminary unit pattern information, and collect the preliminary actual wafer CD data of the wafer under test on the measurement instrument under the preset light source exposure conditions based on the preliminary instrument measurement program. Determine whether the preliminary actual wafer CD meets the preset modeling conditions. If so, establish an initial OPC model based on the current preliminary actual wafer CD data, and take the proposed light source in the current preset light source exposure conditions as the target light source. Take the best focal length and best energy in the energy and focal length change matrix in the current preset light source exposure conditions as the target exposure conditions. Otherwise, adjust the current preset light source exposure conditions to obtain new preset light source exposure conditions, and re-perform optical exposure simulation of the test mask based on the new preset light source exposure conditions.

[0048] Specifically, a preliminary measurement program, established by the machine based on preliminary unit pattern information, is acquired. Then, based on this preliminary measurement program, preliminary actual wafer CD data is collected on the measurement machine after optical exposure under preset light source conditions. This preliminary actual wafer CD data includes the position information of each unit pattern on the wafer and its corresponding linewidth value (i.e., wafer CD data value). Corresponding to the preliminary simulation data, the preliminary actual wafer CD data is the actual CD value collected by the wafer under actual energy and focal length exposure conditions. The energy and focal length variation matrix in the preset light source exposure conditions is an exposure condition achieved through adjustments by the lithography machine. This can be understood as the measurement program automatically collecting actual wafer CD data under different energy and focal length exposure conditions by the lithography machine on the measurement machine. It should be noted that the wafer under test is any wafer corresponding to the exposure using a test mask.

[0049] Then, the acquired preliminary actual wafer CD data is judged based on the preset modeling conditions. If the preliminary actual wafer CD data meets the preset modeling conditions, it means that the current preliminary actual wafer CD data can be used as the data basis for the secondary modeling of the OPC model. If the preliminary actual wafer CD data does not meet the preset modeling conditions, it means that the current preliminary actual wafer CD data does not meet the modeling requirements and cannot be used as the data basis for the secondary modeling of the OPC model.

[0050] In one embodiment, the preset modeling conditions may include: determining whether the image clarity of the preliminary actual wafer CD data is greater than a preset clarity threshold; if so, further determining whether the image of the preliminary actual wafer CD data is complete (i.e., determining whether the image border and other structures are complete); if so, determining that the wafer image quality corresponding to the current preliminary actual wafer CD data is good, and further, that is, the preliminary actual wafer CD data meets the first modeling conditions; if the image clarity of the preliminary actual wafer CD data is not greater than the preset clarity threshold, or the image of the preliminary actual wafer CD data is incomplete, then determining that the wafer image quality corresponding to the current preliminary actual wafer CD data has defects, and the current preliminary actual wafer CD data does not meet the preset modeling conditions.

[0051] After determining that the preliminary actual wafer CD data meets the first modeling condition, it is possible to further determine whether the percentage of the number of unit patterns with linewidths within the first value range in the preliminary actual wafer CD data is greater than a preset percentage threshold. That is, it is to determine whether the linewidths of all unit patterns in the preliminary actual wafer CD data meet the first value range. If the linewidths of some unit patterns do not meet the first value range, it is to determine whether the unit patterns that do not meet the first value range can be ignored. If they can be ignored, or if the percentage of the number of unit patterns with linewidths outside the first value range in the preliminary actual wafer CD data is small, it can be determined that the range of points in the current preliminary actual wafer CD data can determine the size of the process window. Furthermore, the current preliminary actual wafer CD data meets the second modeling condition. If it is determined that the unit pattern that does not meet the first value range cannot be ignored, or the line width of most unit patterns in the preliminary actual wafer CD data does not meet the first value range (i.e., the percentage of unit patterns with line widths not in the first value range in the preliminary actual wafer CD data is relatively large), then it is determined that the range of points in the current preliminary actual wafer CD data cannot determine the size of the process window, and further, the current preliminary actual wafer CD data does not meet the preset modeling conditions.

[0052] After determining that the preliminary actual wafer CD data meets the second modeling condition, it is further determined whether the exposure latitude (EL) and depth of focus (DOF) obtained based on the preliminary actual wafer CD data both meet the preset light source exposure conditions. Specifically, it is determined whether the exposure latitude calculated based on the linewidth values ​​of the unit patterns in the preliminary actual wafer CD data is less than a preset exposure latitude threshold, and whether the depth of focus calculated based on the linewidth values ​​of the unit patterns in the preliminary actual wafer CD data is less than a preset depth of focus threshold. If so, it indicates that both the exposure latitude and depth of focus obtained based on the preliminary actual wafer CD data meet the preset light source exposure conditions, and the current preliminary actual wafer CD data is determined to meet the third modeling condition; otherwise, it is determined that the current preliminary actual wafer CD data does not meet the preset modeling conditions. It should be noted that both exposure latitude and depth of focus are calculated based on the linewidth values ​​of the unit patterns in the preliminary actual wafer CD data. The preset exposure latitude threshold and preset depth of focus threshold can be set based on actual conditions and are not fixed here.

[0053] It should be noted that the preset modeling conditions can also be set to other reasonable conditions based on the actual situation, and no fixed restrictions are imposed on them here.

[0054] Once it is determined that the current preliminary actual wafer CD data meets the preset modeling conditions, the EDA software can be used to construct the initial OPC model based on the current preliminary actual wafer CD data. At the same time, the proposed light source in the current preset light source exposure conditions is taken as the target light source, and the optimal focal length and optimal energy in the energy and focal length change matrix in the current preset light source exposure conditions are taken as the target exposure conditions, so as to set the conditions for subsequent optical exposure. If the current preliminary actual wafer CD data does not meet the preset modeling conditions, it means that OPC modeling cannot be performed based on the current preliminary actual wafer CD data. In this case, the preset light source exposure conditions in step S101 need to be adjusted. Specifically, the energy and focal length change matrix in the preset light source exposure conditions can be adjusted, or the proposed light source in the preset light source exposure conditions can be adjusted, or both the energy and focal length change matrix and the proposed light source in the preset light source exposure conditions can be adjusted at the same time to obtain new preset light source exposure conditions. Then, return to step S101 and use EDA software to perform optical exposure simulation on the test mask again based on the new preset light source exposure conditions to further obtain the corresponding preliminary actual wafer CD data and judge it until preliminary actual wafer CD data that meets the preset modeling conditions is obtained.

[0055] Step S103: Under the target light source and target exposure conditions, perform optical exposure simulation on the test mask based on the initial OPC model to obtain re-simulation data, and filter the unit patterns in the re-simulation data based on the second screening condition to obtain re-unit pattern information.

[0056] Specifically, based on the constructed initial OPC model, the test mask is simulated under the target light source and standard exposure conditions to obtain re-simulation data. This re-simulation data includes the target linewidth and the positional information of the cell patterns corresponding to the simulated values ​​near the target linewidth.

[0057] A second filtering condition is pre-defined, including the target linewidth and a second value range encompassing the target linewidth. This second value range is typically set based on the target linewidth; for example, the left endpoint of the second value range could be the target linewidth minus a specific value, and the right endpoint could be the target linewidth plus a specific value. Then, the re-simulated data is filtered based on the second filtering condition to identify all unit image information whose linewidths satisfy the second value range. This selected unit image information is then aggregated into re-unit pattern information. The data aggregation degree of the re-unit pattern information obtained from the second value range (i.e., the obtained linewidth is closer to the target linewidth) should be higher than that of the initial unit pattern information obtained from the first value range. Therefore, the second value range should be set to be smaller than the first value range. This setting ensures the accuracy of the re-simulated data while reducing data processing volume.

[0058] The second screening condition can also be implemented in the form of a second intelligent measurement script, that is, by using the second intelligent measurement script to extract data from the re-simulated data, so as to screen out all unit pattern information that meets the second value range from the re-simulated data.

[0059] Step S104: Obtain the re-measurement program based on the re-unit pattern information, collect the actual wafer CD data of the wafer under test on the measurement machine under the target light source and target exposure conditions based on the re-measurement program, and establish the final OPC model based on the actual wafer CD data.

[0060] Specifically, a machine measurement program that can be identified by the machine is obtained based on the re-unit pattern information. Then, based on the re-measurement program, the actual wafer CD data of the wafer under test after optical exposure under the target light source and target exposure conditions is collected on the measurement machine. Finally, EDA software is used to build the final OPC model based on the actual wafer CD data. It should be noted that using EDA software to build the OPC model is a conventional method. For example, the actual wafer CD data needs to be processed first to filter out the target values ​​suitable for ADI and remove the linewidth values ​​that do not meet the requirements. Then, based on the standard deviation of the measurement data, the normalized image logarithmic slope NILS and pattern are classified and assigned different weights. Finally, the data of different types and weights are fitted to obtain the final OPC model, etc. This embodiment will not explain the details further.

[0061] In one embodiment, the OPC model construction method of this embodiment differs from the above embodiment in that a step S100 is set before step S101.

[0062] It should be noted that the process of manually establishing a preliminary machine measurement program based on preliminary unit pattern information and manually establishing a secondary machine measurement program based on secondary unit pattern information is a standard procedure in this field, and will not be elaborated upon here.

[0063] Step S100: Name each unit pattern on the test mask.

[0064] That is, each unit pattern on the test mask is named at the beginning of the design process, so that the location information of the unit pattern can be obtained based on the name information in subsequent steps. At this time, the unit pattern location information in the initial unit pattern information and the subsequent unit pattern information can be replaced with the unit pattern name information. This setting makes the obtained unit pattern information clear and easy to understand, and reduces the risk of errors.

[0065] The OPC model construction method provided in this invention obtains preliminary cell pattern information by optically exposing and initially screening a test mask. Then, based on this preliminary cell pattern information, preliminary actual wafer CD data is obtained and screened according to modeling conditions to ensure the coverage of the current design pattern. Finally, the test mask is optically exposed based on the initial OPC model established through modeling condition screening, and the data obtained from the exposure is further refined to make the collected measurement data more representative, achieving the purpose of selecting appropriate data for fitting and calibration, and ensuring the accuracy of the final OPC model. This invention adopts an intelligent measurement method that optimizes existing manual measurement methods while improving measurement efficiency and reducing errors caused by human factors. Measurement results are all based on optical model data, which can improve the accuracy of the model. The cell patterns in the test mask are named to facilitate subsequent screening of cell pattern information based on screening conditions, realizing an intelligent improvement in cell pattern and measurement data collection. In this embodiment, the design gauge of the actual Test Mask is exported before data collection begins. Based on the design gauge, a measurement program is intelligently established to collect data, thereby optimizing the results of the OPC model and making it closer to the actual experimental results.

[0066] like Figure 2 As shown, this embodiment provides an OPC model construction device, including a preliminary unit pattern information acquisition module, an initial OPC model acquisition module, a secondary unit pattern information acquisition module, and a final OPC model establishment module.

[0067] The preliminary unit pattern information acquisition module is used to perform optical exposure simulation on the test mask based on preset light source exposure conditions to obtain preliminary simulation data. Based on the first screening condition, the unit patterns in the preliminary simulation data are screened to obtain preliminary unit pattern information. The preset light source exposure conditions include the proposed light source and the energy and focal length variation matrix.

[0068] The initial OPC model acquisition module is used to acquire the preliminary instrumentation program established based on the preliminary unit pattern information, and to collect the preliminary actual wafer CD data of the wafer under test on the instrumentation machine under the preset light source exposure conditions based on the preliminary instrumentation program. It determines whether the preliminary actual wafer CD meets the preset modeling conditions. If so, it establishes an initial OPC model based on the current preliminary actual wafer CD data, and takes the proposed light source in the current preset light source exposure conditions as the target light source, and takes the best focal length and best energy in the energy and focal length change matrix in the current preset light source exposure conditions as the target exposure conditions. Otherwise, it adjusts the current preset light source exposure conditions to obtain new preset light source exposure conditions, and re-performs optical exposure simulation on the test mask based on the new preset light source exposure conditions.

[0069] The re-unit pattern information is used to perform optical exposure simulation on the test mask based on the initial OPC model under the target light source and target exposure conditions to obtain re-simulation data. The unit patterns in the re-simulation data are then filtered based on the second filtering condition to obtain the re-unit pattern information.

[0070] The final OPC model building module is used to obtain the re-machine measurement program based on the re-cell pattern information. Based on the re-machine measurement program, the actual wafer CD data of the wafer under test is collected on the measurement machine under the target light source and target exposure conditions. The final OPC model is built based on the actual wafer CD data.

[0071] The wafer to be tested is any wafer that has been exposed using a test mask.

[0072] The OPC model building apparatus provided in this invention obtains preliminary cell pattern information by optically exposing and initially screening a test mask. Then, based on the preliminary cell pattern information, it obtains preliminary actual wafer CD data and filters it according to modeling conditions to ensure the coverage of the current design pattern. Finally, based on the initial OPC model established after modeling condition filtering, it optically exposes the test mask and further refines the data obtained from the exposure, making the collected measurement data more representative and achieving the purpose of selecting appropriate data for fitting and calibration, thus ensuring the accuracy of the final OPC model. This invention adopts an intelligent measurement method that optimizes existing manual measurement methods while improving measurement efficiency and reducing errors caused by human factors. Measurement results are all based on optical model data, which can improve the accuracy of the model. The cell patterns in the test mask are named to facilitate subsequent filtering of cell pattern information based on screening conditions, realizing an intelligent improvement in cell pattern and measurement data collection.

[0073] This application also provides a computer-readable storage medium. Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing a processor. The program can be stored in a computer-readable storage medium, which is a non-transitory medium, such as random access memory, read-only memory, flash memory, hard disk, solid-state drive, magnetic tape, floppy disk, optical disk, and any combination thereof. The storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. This available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital video disc (DVD)), or a semiconductor medium (e.g., solid-state drive (SSD)).

[0074] like Figure 3 As shown, this application provides a terminal.

[0075] The terminal in this embodiment includes a processor and a memory connected to each other; the memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory, so that the terminal can implement all or part of the steps in the method of the above embodiment when it is executed.

[0076] The beneficial effects of all or part of the steps of the above embodiments are the same as the beneficial effects obtained by the terminal provided by the embodiments of the present invention, and will not be described again here.

[0077] It should be noted that the memory may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. Similarly, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0078] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for constructing an OPC model, comprising: The test mask is subjected to optical exposure simulation based on preset light source exposure conditions to obtain preliminary simulation data. The unit patterns in the preliminary simulation data are filtered based on the first screening condition to obtain preliminary unit pattern information. The preset light source exposure conditions include the proposed light source and energy and focal length variation matrix. A preliminary instrumentation program is obtained based on the preliminary unit pattern information. Based on the preliminary instrumentation program, preliminary actual wafer CD data of the wafer under test is collected on the instrument under the preset light source exposure conditions. It is determined whether the preliminary actual wafer CD meets the preset modeling conditions. If so, an initial OPC model is established based on the current preliminary actual wafer CD data. The proposed light source in the current preset light source exposure conditions is taken as the target light source, and the optimal focal length and optimal energy in the energy and focal length change matrix of the current preset light source exposure conditions are taken as the target exposure conditions. Otherwise, the current preset light source exposure conditions are adjusted to obtain new preset light source exposure conditions, and the optical exposure simulation of the test mask is performed again based on the new preset light source exposure conditions. Under the target light source and the target exposure conditions, the test mask is subjected to optical exposure simulation based on the initial OPC model to obtain re-simulation data, and the unit patterns in the re-simulation data are filtered based on the second filtering condition to obtain re-unit pattern information; A re-measurement program based on the re-unit pattern information is obtained. Based on the re-measurement program, the actual wafer CD data of the wafer under test is collected on the measurement machine under the target light source and the target exposure conditions. The final OPC model is established based on the actual wafer CD data. The wafer to be tested is any wafer that has been exposed using the test mask.

2. The method according to claim 1, characterized in that, Before the step of performing optical exposure simulation on the test mask based on preset light source exposure conditions to obtain preliminary simulation data, and filtering the unit patterns in the preliminary simulation data based on the first filtering condition to obtain preliminary unit pattern information, the following steps are also included: Name each unit pattern on the test mask; Both the preliminary unit pattern information and the secondary unit pattern information include the name information of the selected unit patterns.

3. The method according to claim 1, characterized in that, The preset modeling conditions include: The image containing the preliminary actual wafer CD data has a resolution greater than a preset resolution threshold, and the image containing the preliminary actual wafer CD data is complete. In the preliminary actual wafer CD data, the percentage of the number of unit patterns with linewidth in the first value range to the total number of unit images is greater than a preset percentage threshold. The exposure latitude and focus depth obtained from the preliminary actual wafer CD data both meet the preset light source exposure conditions.

4. The method according to claim 1, characterized in that, The first filtering condition includes the target line width and a first value range that includes the target line width.

5. The method according to claim 4, characterized in that, The second filtering condition includes a target line width and a second value range that includes the target line width, wherein the second value range is smaller than the first value range.

6. The method according to claim 1, characterized in that, Both the initial OPC model and the final OPC model were established using EDA software.

7. The method according to claim 1, characterized in that, The proposed light source is obtained through simulation using EDA software based on the proposed light source information.

8. An OPC model building device, characterized in that, It includes a module for acquiring preliminary unit pattern information, a module for acquiring initial OPC model, a module for acquiring secondary unit pattern information, and a module for establishing the final OPC model; The preliminary unit pattern information acquisition module is used to perform optical exposure simulation on the test mask based on preset light source exposure conditions to obtain preliminary simulation data, and to filter the unit patterns in the preliminary simulation data based on the first screening condition to obtain preliminary unit pattern information. The preset light source exposure condition includes a proposed light source and an energy and focal length variation matrix. The initial OPC model acquisition module is used to acquire a preliminary instrumentation program established based on the preliminary unit pattern information, and to collect preliminary actual wafer CD data of the wafer under test on the instrumentation machine under the preset light source exposure conditions based on the preliminary instrumentation program. It determines whether the preliminary actual wafer CD meets the preset modeling conditions. If so, it establishes an initial OPC model based on the current preliminary actual wafer CD data, and takes the proposed light source in the current preset light source exposure conditions as the target light source, and takes the best focal length and best energy in the energy and focal length change matrix in the current preset light source exposure conditions as the target exposure conditions. Otherwise, it adjusts the current preset light source exposure conditions to obtain new preset light source exposure conditions, and re-performs optical exposure simulation on the test mask based on the new preset light source exposure conditions. The re-unit pattern information is used to perform optical exposure simulation on the test mask based on the initial OPC model under the target light source and the target exposure conditions to obtain re-simulation data, and to filter the unit patterns in the re-simulation data based on the second filtering condition to obtain re-unit pattern information. The final OPC model building module is used to obtain a re-machine measurement program based on the re-unit pattern information, collect the actual wafer CD data of the wafer under test on the measurement machine under the target light source and the target exposure conditions based on the re-machine measurement program, and build the final OPC model based on the actual wafer CD data. The wafer to be tested is any wafer that has been exposed using the test mask.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the OPC model construction method according to any one of claims 1 to 7.

10. A terminal, 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 OPC model construction method according to any one of claims 1 to 7.

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