OPC model construction method and device, computer readable storage medium and terminal

Abstract

The invention discloses an OPC model construction method and device, a storage medium and a terminal, and the method comprises the steps: carrying out the optical exposure simulation of a test mask, so as to obtain preliminary simulation data, and screening unit patterns in the preliminary simulation data based on a first screening condition, so as to obtain preliminary unit pattern information; acquiring a preliminary machine measurement program established on the basis of the preliminary unit pattern information, collecting preliminary actual wafer CD data of the wafer to be measured on the basis of the preliminary machine measurement program, and judging the preliminary actual wafer CD on the basis of a preset modeling condition to establish an initial OPC model; simulating the test mask based on the initial OPC model to obtain secondary simulation data, and screening unit patterns in the secondary simulation data based on a second screening condition to obtain secondary unit pattern information; a final OPC model is obtained based on the secondary cell pattern information. By adopting an intelligent measurement mode, the measurement efficiency is improved and errors caused by human factors are reduced while the existing manual participation measurement mode is optimized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to an OPC model building method and related devices. Background Art

[0002] With the advancement of semiconductor process technology, the amount of measurement data required to develop OPC models for advanced nodes is gradually increasing. Since each feature process in the semiconductor process is relatively independent, a corresponding independent OPC optimization model must be established for each feature process to obtain more accurate results, so the amount of data required on both sides will be larger. The conventional OPC model establishment process is: first collect a large amount of CD-SEM measurement data, and then fit and optimize the measurement data to calibrate the established OPC model, so that the calculation results of the lithography model are consistent with the actual experimental results.

[0003] The collection of actual measurement data needs to be achieved through a high-resolution electron microscope. Therefore, daily actual measurement data needs to be collected by manpower in large quantities. The measurement operation based on labor costs is not only time-consuming and labor-intensive, but also prone to errors, which in turn affects the accuracy of the final OPC model established. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, the purpose of the present application is to provide an OPC model construction method and device, a computer-readable storage medium and a terminal, which are used to solve the problem that the existing OPC model construction requires a large amount of manpower cost, which is not only time-consuming and labor-intensive, but also prone to errors, thus affecting the accuracy of the established OPC model.

[0005] In a first aspect, the present application provides an OPC model construction method, comprising:

[0006] Performing optical exposure simulation on the test mask based on a preset light source exposure condition to obtain preliminary simulation data, and screening the unit pattern in the preliminary simulation data based on a first screening condition to obtain preliminary unit pattern information, wherein the preset light source exposure condition includes a proposed light source and an energy and focal length variation matrix;

[0007] Acquire a preliminary machine measurement program established based on the preliminary unit pattern information, and collect preliminary actual wafer CD data of the wafer to be tested under the preset light source exposure condition on the measurement machine based on the preliminary machine measurement program, determine whether the preliminary actual wafer CD meets the preset modeling condition, if so, establish an initial OPC model based on the current preliminary actual wafer CD data, and use the proposed light source in the current preset light source exposure condition as the target light source, and use the optimal focal length and optimal energy in the energy and focal length variation matrix in the current preset light source exposure condition as the target exposure condition, otherwise adjust the current preset light source exposure condition to obtain a new preset light source exposure condition, and re-perform optical exposure simulation on the test mask based on the new preset light source exposure condition;

[0008] Under the target light source and the target exposure condition, performing optical exposure simulation on the test mask based on the initial OPC model to obtain re-simulation data, and screening unit patterns in the re-simulation data based on a second screening condition to obtain re-unit pattern information;

[0009] Acquire a secondary machine measurement program established based on the secondary unit pattern information, collect secondary actual wafer CD data of the wafer to be tested under the target light source and the target exposure conditions on the measurement machine based on the secondary machine measurement program, and establish a final OPC model based on the secondary actual wafer CD data;

[0010] The wafer to be tested is any wafer corresponding to the wafer exposed by the test mask.

[0011] In one embodiment of the present application, optical exposure simulation is performed on the test mask based on a preset light source exposure condition to obtain preliminary simulation data, and before the step of screening the unit pattern in the preliminary simulation data based on the first screening condition to obtain preliminary unit pattern information, the step further includes:

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

[0013] The preliminary unit pattern information and the secondary unit pattern information both include name information of the filtered unit patterns.

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

[0015] The clarity of the picture where the preliminary actual wafer CD data is located is greater than a preset clarity threshold, and the picture where the preliminary actual wafer CD data is located is complete;

[0016] The percentage of the number of unit patterns with line widths in the first value range in the preliminary actual wafer CD data to the total number of unit images is greater than a preset percentage threshold;

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

[0018] In an embodiment of the present application, the first screening condition includes a target line width and a first value range including the target line width.

[0019] In an embodiment of the present application, the second screening condition includes a target line width and a second value range including the target line width, and the second value range is smaller than the first value range.

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

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

[0022] In a second aspect, the present 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 and 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 a preset light source exposure condition to obtain preliminary simulation data, and to screen the unit patterns in the preliminary simulation data based on a first screening condition to obtain preliminary unit pattern information, wherein 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 machine measurement program established based on the preliminary unit pattern information, and collect preliminary actual wafer CD data of the wafer to be tested under the preset light source exposure condition on the measurement machine based on the preliminary machine measurement program, and judge whether the preliminary actual wafer CD meets the preset modeling condition. If so, an initial OPC model is established based on the current preliminary actual wafer CD data, and the proposed light source in the current preset light source exposure condition is used as the target light source, and the optimal focal length and optimal energy in the energy and focal length variation matrix in the current preset light source exposure condition are used as the target exposure condition; otherwise, the current preset light source exposure condition is adjusted to obtain a new preset light source exposure condition, and the optical exposure simulation of the test mask is re-performed based on the new preset light source exposure condition;

[0025] The secondary 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 condition to obtain secondary simulation data, and to filter the unit pattern in the secondary simulation data based on the second filtering condition to obtain the secondary unit pattern information;

[0026] The final OPC model establishment module is used to obtain a secondary machine measurement program established based on the secondary unit pattern information, collect secondary actual wafer CD data of the wafer to be tested under the target light source and the target exposure conditions on the measurement machine based on the secondary machine measurement program, and establish a final OPC model based on the secondary actual wafer CD data;

[0027] The wafer to be tested is any wafer corresponding to the wafer exposed by the test mask.

[0028] In a third aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the OPC model building method when executed by a processor.

[0029] In a fourth aspect, the present application also provides a terminal, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the OPC model building method.

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

[0031] The OPC model construction method provided by the embodiment of the present invention is applied to obtain preliminary unit pattern information by optically exposing the test mask and performing preliminary screening, and then obtaining preliminary actual wafer CD data based on the preliminary unit pattern information and screening it based on the modeling conditions to ensure the coverage capability of the current design graphics. Finally, the test mask is optically exposed based on the initial OPC model established after modeling condition screening, and the data obtained by exposure is further refined and screened, so that the collected measurement data is more representative, and the purpose of fitting and calibrating the data in the appropriate range is achieved, so as to ensure the accuracy of the final OPC model obtained. The present invention adopts an intelligent measurement method to optimize the existing manual measurement method, while also improving the measurement efficiency and reducing the errors caused by human factors. The measurement results all use optical model data as the judgment basis, which can improve the accuracy of the model. The unit patterns in the test mask are named to facilitate the subsequent screening of unit pattern information based on screening conditions, so as to realize the intelligent improvement of unit graphics and measurement data collection.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 Shown is a flow chart of the OPC model building method described in an embodiment of the present application.

[0035] Figure 2 Shown is a schematic diagram of the structure of the OPC model building device described in an embodiment of the present application.

[0036] Figure 3 Shown is a schematic diagram of the structure of the terminal described in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application 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 application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0038] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

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

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

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

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

[0043] Specifically, determine the test mask to be tested (i.e., Test mask). The test mask is usually set in advance based on the requirements. The test mask is designed with multiple and various types of unit patterns (i.e., gauges). Each unit pattern has corresponding position information on the test mask. At the same time, obtain the preset light source exposure conditions, which include the proposed light source, energy, and focal length change matrix. EDA software (Electronic Design Automation) can simulate the proposed light source and energy and focal length change matrix based on the preset light source exposure conditions.

[0044] The proposed light source simulated by the EDA software is used to perform optical exposure simulation on the test mask under the exposure conditions of the energy and focal length variation matrix to obtain simulation data; all the obtained simulation data are collected as preliminary simulation data. The preliminary simulation data specifically includes the position information of each unit image in the test mask and the line width value of each unit image (i.e., the wafer CD data value).

[0045] The first screening condition is set in advance. The first screening condition includes the target line width and the first value range including the target line width. The first value range is usually set based on the target line width. For example, the target line width minus the preset value is used as the left end point of the first value range, and the target line width plus the preset value is used as the right end point of the first value range. Then, the preliminary simulation data is screened based on the first screening condition to screen out all unit image information (specifically, the position information of the unit image) in the preliminary simulation data whose line width meets the first value range, and the screened unit image information is collected as preliminary unit pattern information. The first value range can usually be set based on the number of screened unit images being about ten percent of the total number of unit images of 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 may be implemented in the form of a first intelligent measurement script, that is, data is extracted from the preliminary simulation data through the first intelligent measurement script to screen out all unit pattern information that meets the first value range from the preliminary simulation data.

[0047] Step S102, obtaining a preliminary machine measurement program established based on the preliminary unit pattern information, and collecting preliminary actual wafer CD data of the wafer to be tested under the preset light source exposure conditions on the measurement machine based on the preliminary machine measurement program, and judging whether the preliminary actual wafer CD meets the preset modeling conditions. If so, establishing an initial OPC model based on the current preliminary actual wafer CD data, and taking the proposed light source in the current preset light source exposure conditions as the target light source, and taking the optimal focal length and optimal energy in the energy and focal length variation matrix in the current preset light source exposure conditions as the target exposure conditions, otherwise adjusting the current preset light source exposure conditions to obtain new preset light source exposure conditions, and re-performing optical exposure simulation on the test mask based on the new preset light source exposure conditions.

[0048] Specifically, a preliminary machine measurement program that can be recognized by the machine is obtained based on the preliminary unit pattern information. Then, based on the preliminary measurement program, the preliminary actual wafer CD data of the wafer to be tested after optical exposure under the preset light source exposure conditions is collected on the measurement machine. The preliminary actual wafer CD data includes the position information of each unit pattern on the wafer to be tested and the corresponding line width 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 from the wafer to be tested under the exposure conditions of actual energy and focal length. Among them, the energy and focal length change matrix in the preset light source exposure conditions is an exposure condition achieved by adjusting the lithography machine, which can be understood as the machine measurement program automatically collecting the actual wafer CD data under the exposure conditions of different energies and focal lengths of the lithography machine on the measurement machine. It should be noted that the wafer to be tested is any wafer corresponding to the exposure using the test mask.

[0049] Then, the obtained 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 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 has not met the modeling requirements and cannot be used as the data basis for secondary modeling of the OPC model.

[0050] In one embodiment, the preset modeling conditions can be set to include: determining whether the clarity of the picture where the preliminary actual wafer CD data is located is greater than the preset clarity threshold, and if so, further determining whether the picture where the preliminary actual wafer CD data is located is complete (i.e., determining whether the structure such as the picture frame is complete), and if so, determining that the wafer image quality corresponding to the current preliminary actual wafer CD data is intact, and further that the preliminary actual wafer CD data meets the first modeling condition; if the clarity of the picture where the preliminary actual wafer CD data is located is not greater than the preset clarity threshold, or the picture where the preliminary actual wafer CD data is located 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, you can continue to determine whether the percentage of the number of unit patterns with line widths in the first value range in the preliminary actual wafer CD data to the total number of unit images is greater than the preset percentage threshold, that is, determine whether the line widths of all unit patterns in the preliminary actual wafer CD data meet the first value range. If there are some unit patterns whose line width values ​​do not meet the first value range, then determine whether the unit patterns that do not meet the first value range can be ignored. If they can be ignored, or the percentage of the number of unit patterns with line widths not in the first value range in the preliminary actual wafer CD data to the total number of unit images is small, then it can be determined that the range of the midpoint of the current preliminary actual wafer CD data can determine the size of the process window, and further that the current preliminary actual wafer CD data meets the second modeling condition. If it is determined that the unit patterns that do not meet the first value range cannot be ignored or the line widths of most unit patterns in the previous preliminary actual wafer CD data do not meet the first value range (that is, the number of unit patterns whose line widths in the preliminary actual wafer CD data are not in the first value range accounts for a large percentage of the total number of unit images), then it is determined that the range of the midpoints of 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 can be further determined whether the exposure latitude (EL: Exposure Latitude) and depth of focus (DOF: depth of focus) obtained based on the preliminary actual wafer CD data meet the preset light source exposure condition, and further determine whether the exposure latitude calculated based on the line width value of the unit pattern in the preliminary actual wafer CD data is less than the preset exposure latitude threshold, and determine whether the depth of focus calculated based on the line width value of the unit pattern in the preliminary actual wafer CD data is less than the preset depth of focus threshold. If so, it means that the exposure latitude and depth of focus obtained based on the preliminary actual wafer CD data meet the preset light source exposure condition, and further determine that the current preliminary actual wafer CD data meets the third modeling condition, otherwise it is determined that the current preliminary actual wafer CD data does not meet the preset modeling condition. It should be noted that the exposure latitude and depth of focus are both calculated based on the line width value of the unit pattern in the preliminary actual wafer CD data. The preset exposure latitude threshold and the preset depth of focus threshold can be set based on actual conditions, and no fixed restrictions are imposed on them here.

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

[0054] When 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 condition is used 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 condition are used as the target exposure conditions, which are used as the setting conditions for subsequent optical exposure. When it is determined that the current preliminary actual wafer CD data does not meet the preset modeling conditions, it means that the OPC model cannot be modeled based on the current preliminary actual wafer CD data. At this time, 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 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, and then return to step S101, use EDA software to re-perform optical exposure simulation on the test mask based on the new preset light source exposure conditions, further obtain the corresponding preliminary actual wafer CD data, and judge it until the 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, optical exposure simulation is performed on the test mask based on the initial OPC model to obtain re-simulation data, and unit patterns in the re-simulation data are screened 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 proposed light source and standard exposure conditions to obtain re-simulation data, wherein the re-simulation data includes position information of unit patterns corresponding to the target line width and the simulated value near the target line width.

[0057] The second screening condition is set in advance. The second screening condition includes the target line width and the second value range including the target line width. The second value range is usually set based on the target line width. For example, the target line width minus a specific value is used as the left end point of the second value range, and the target line width plus a specific value is used as the right end point of the second value range. Then, the re-simulated data is screened based on the second screening condition to screen out all the unit image information in the re-simulated data whose line width meets the second value range, and the screened unit image information is aggregated into the re-unit pattern information. The data aggregation degree of the re-unit pattern information obtained by the second value range (that is, the obtained line width is closer to the target line width) should be higher than the preliminary unit pattern information obtained by 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 the amount of data processing.

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

[0059] In step S104, a secondary machine measurement program established based on the secondary unit pattern information is obtained, and secondary actual wafer CD data of the wafer to be tested under the target light source and target exposure conditions is collected on the measurement machine based on the secondary machine measurement program, and a final OPC model is established based on the secondary actual wafer CD data.

[0060] Specifically, a re-machine measurement program that can be recognized by the machine established based on the re-unit pattern information is obtained, and then the actual wafer CD data of the wafer to be tested after optical exposure under the target light source and target exposure conditions is collected on the measurement machine based on the re-measurement program. Finally, the final OPC model is established based on the actual wafer CD data again using EDA software. It should be noted that the use of EDA software to construct an OPC model is a conventional means. For example, the actual wafer CD data again needs to be processed first to screen out the target value suitable for ADI and remove the line width values ​​that do not meet the requirements in the actual wafer CD data again; 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, data of different types and weights are fitted to obtain the final OPC model, etc. This embodiment does not explain it too much here.

[0061] In one embodiment, the OPC model building method of this embodiment is different from the above embodiment in that step S100 is further provided before step S101.

[0062] It should be noted that manually establishing a preliminary machine measurement program based on the preliminary unit pattern information and manually establishing a secondary machine measurement program based on the secondary unit pattern information are conventional processes in the art and will not be described in detail herein.

[0063] Step S100, naming each unit pattern on the test mask.

[0064] That is, at the beginning of designing the test mask, each unit pattern on the test mask is named, so that the unit pattern position information can be obtained based on the unit pattern name information in the subsequent steps. At this time, the unit pattern position information in the preliminary unit pattern information and the secondary unit pattern information in the above steps can be replaced with the unit pattern name information. This setting can make the obtained unit pattern information clear and not prone to errors.

[0065] The OPC model construction method provided by the embodiment of the present invention obtains preliminary unit pattern information by optically exposing the test mask and performing preliminary screening, and then obtains preliminary actual wafer CD data based on the preliminary unit pattern information and screens it based on the modeling conditions to ensure the coverage capability of the current design graphics, and finally optically exposes the test mask based on the initial OPC model established after the modeling condition screening, and further refines the data obtained by the exposure, so that the collected measurement data is more representative, and the purpose of fitting and calibrating the data in the appropriate range is achieved, so as to ensure the accuracy of the final OPC model obtained. The present invention adopts an intelligent measurement method to optimize the existing manual measurement method, while also improving the measurement efficiency and reducing the errors caused by human factors. The measurement results all use optical model data as the judgment basis, which can improve the accuracy of the model. The unit patterns in the test mask are named to facilitate the subsequent screening of the unit pattern information based on the screening conditions, so as to realize the intelligent improvement of the unit graphics and measurement data collection. The method of this embodiment first exports the design gauge of the actual Test Mask before starting to collect data, and intelligently establishes a measurement program based on the design gauge to collect data, thereby optimizing the results of the OPC model to make it closer to the actual experimental results.

[0066] like Figure 2 As shown, this embodiment 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 and final OPC model building 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, and to filter the unit patterns in the preliminary simulation data based on the first screening conditions to obtain preliminary unit pattern information. The preset light source exposure conditions include a proposed light source and energy and focal length change matrix.

[0068] The initial OPC model acquisition module is used to obtain a preliminary machine measurement program established based on preliminary unit pattern information, and based on the preliminary machine measurement program, collect preliminary actual wafer CD data of the wafer to be tested under preset light source exposure conditions on the measurement machine, and judge 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, and the proposed light source in the current preset light source exposure conditions is used 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 used 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 re-performed based on the new preset light source exposure conditions.

[0069] The secondary 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 secondary simulation data, and to filter the unit patterns in the secondary simulation data based on the second filtering condition to obtain the secondary unit pattern information.

[0070] The final OPC model building module is used to obtain a secondary machine measurement program established based on the secondary unit pattern information, collect secondary actual wafer CD data of the wafer to be tested under the target light source and target exposure conditions on the measurement machine based on the secondary machine measurement program, and establish the final OPC model based on the secondary actual wafer CD data;

[0071] The wafer to be tested is any wafer corresponding to the wafer exposed by the test mask.

[0072] The OPC model building device provided by the embodiment of the present invention obtains preliminary unit pattern information by optically exposing the test mask and performing preliminary screening, and then obtains preliminary actual wafer CD data based on the preliminary unit pattern information and screens it based on the modeling conditions to ensure the coverage capability of the current design graphics, and finally optically exposes the test mask based on the initial OPC model established after the modeling condition screening, and further refines the data obtained by the exposure, so that the collected measurement data is more representative, and the purpose of fitting and calibrating the data in the appropriate range is achieved, so as to ensure the accuracy of the final OPC model obtained. The present invention adopts an intelligent measurement method to optimize the existing manual measurement method, while also improving the measurement efficiency and reducing the errors caused by human factors. The measurement results all use optical model data as the judgment basis, which can improve the accuracy of the model. The unit patterns in the test mask are named to facilitate the subsequent screening of the unit pattern information based on the screening conditions, so as to realize the intelligent improvement of the unit graphics and measurement data collection.

[0073] The present application embodiment also provides a computer-readable storage medium. A person of ordinary skill in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the processor through a program, and the program can be stored in a computer-readable storage medium, and the storage medium is a non-transitory medium, such as a random access memory, a read-only memory, a flash memory, a hard disk, a solid-state hard disk, a magnetic tape, a floppy disk, an optical disc, and any combination thereof. The above-mentioned storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a digital video disc (DVD)), or a semiconductor medium (for example, a solid-state disk (SSD)), etc.

[0074] like Figure 3 As shown, an embodiment of the present application provides a terminal.

[0075] The terminal of 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 all or part of the steps in the method of the above embodiment can be implemented when the terminal executes.

[0076] The beneficial effects of all or part of the steps of the method in the above embodiment are the same as the beneficial effects obtained by applying the terminal provided by the embodiment of the present invention, and will not be described in detail 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. Similarly, the processor may also be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may 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 gates or transistor logic devices, discrete hardware components.

[0078] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. An OPC model construction method, comprising: Performing optical exposure simulation on the test mask based on a preset light source exposure condition to obtain preliminary simulation data, and screening the unit pattern in the preliminary simulation data based on a first screening condition to obtain preliminary unit pattern information, wherein the preset light source exposure condition includes a proposed light source and an energy and focal length variation matrix; Acquire a preliminary machine measurement program established based on the preliminary unit pattern information, and collect preliminary actual wafer CD data of the wafer to be tested under the preset light source exposure condition on the measurement machine based on the preliminary machine measurement program, determine whether the preliminary actual wafer CD meets the preset modeling condition, if so, establish an initial OPC model based on the current preliminary actual wafer CD data, and use the proposed light source in the current preset light source exposure condition as the target light source, and use the optimal focal length and optimal energy in the energy and focal length variation matrix in the current preset light source exposure condition as the target exposure condition, otherwise adjust the current preset light source exposure condition to obtain a new preset light source exposure condition, and re-perform optical exposure simulation on the test mask based on the new preset light source exposure condition; Under the target light source and the target exposure condition, performing optical exposure simulation on the test mask based on the initial OPC model to obtain re-simulation data, and screening unit patterns in the re-simulation data based on a second screening condition to obtain re-unit pattern information; Acquire a secondary machine measurement program established based on the secondary unit pattern information, collect secondary actual wafer CD data of the wafer to be tested under the target light source and the target exposure conditions on the measurement machine based on the secondary machine measurement program, and establish a final OPC model based on the secondary actual wafer CD data; The wafer to be tested is any wafer corresponding to the wafer exposed by the test mask.

2. The method according to claim 1, characterized in that The step of performing optical exposure simulation on the test mask based on a preset light source exposure condition to obtain preliminary simulation data, and screening the unit pattern in the preliminary simulation data based on the first screening condition to obtain preliminary unit pattern information also includes: Naming each unit pattern on the test mask; The preliminary unit pattern information and the secondary unit pattern information both include name information of the filtered unit patterns.

3. The method according to claim 1, characterized in that The preset modeling conditions include: The clarity of the picture where the preliminary actual wafer CD data is located is greater than a preset clarity threshold, and the picture where the preliminary actual wafer CD data is located is complete; The percentage of the number of unit patterns with line widths in the first value range in the preliminary actual wafer CD data to the total number of unit images is greater than a preset percentage threshold; The exposure latitude and focus depth obtained based on 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 screening condition includes a target line width and a first value range including the target line width.

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

6. The method according to claim 1, characterized in that The initial OPC model and the final OPC model are both established through EDA software.

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

8. An OPC model building device, characterized in that: It includes a preliminary unit pattern information acquisition module, an initial OPC model acquisition module, a secondary unit pattern information and final OPC model establishment module; The preliminary unit pattern information acquisition module is used to perform optical exposure simulation on the test mask based on a preset light source exposure condition to obtain preliminary simulation data, and to screen the unit patterns in the preliminary simulation data based on a first screening condition to obtain preliminary unit pattern information, wherein 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 machine measurement program established based on the preliminary unit pattern information, and collect preliminary actual wafer CD data of the wafer to be tested under the preset light source exposure condition on the measurement machine based on the preliminary machine measurement program, and judge whether the preliminary actual wafer CD meets the preset modeling condition. If so, an initial OPC model is established based on the current preliminary actual wafer CD data, and the proposed light source in the current preset light source exposure condition is used as the target light source, and the optimal focal length and optimal energy in the energy and focal length variation matrix in the current preset light source exposure condition are used as the target exposure condition; otherwise, the current preset light source exposure condition is adjusted to obtain a new preset light source exposure condition, and the optical exposure simulation of the test mask is re-performed based on the new preset light source exposure condition; The secondary 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 condition to obtain secondary simulation data, and to filter the unit pattern in the secondary simulation data based on the second filtering condition to obtain the secondary unit pattern information; The final OPC model establishment module is used to obtain a secondary machine measurement program established based on the secondary unit pattern information, collect secondary actual wafer CD data of the wafer to be tested under the target light source and the target exposure conditions on the measurement machine based on the secondary machine measurement program, and establish a final OPC model based on the secondary actual wafer CD data; The wafer to be tested is any wafer corresponding to the wafer exposed by 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, the OPC model building method according to any one of claims 1 to 7 is implemented.

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 building method according to any one of claims 1 to 7.

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