Photolithography model establishing method, device, equipment, medium and product

Abstract

The application discloses a method and device for establishing a photolithography model, equipment, a medium and a product, and is applied to the field of photolithography technology. The method first determines two optimal preset plane positions; then compensates the optimal preset focus plane position based on offset information between an actual critical dimension and a simulation critical dimension. Further, a target metrology plane position is determined based on a line width difference value; and finally, the photolithography model is established based on the target focus plane position and the target metrology plane position. The scheme provided in the embodiment determines the offset information and compensates the optimal preset focus plane, eliminates the error between the actual physical exposure and the model simulation, further re-determines the optimal metrology plane position, so that the accurate establishment parameters of the photolithography model can be obtained, and the accuracy and efficiency of photolithography modeling are ensured.

Description

Technical Field

[0001] The present application relates to the field of photolithography technology, and in particular to a method, device, equipment, medium and product for establishing a photolithography model. Background Art

[0002] The lithography model consists of two parts: the optical model and the etching model. Establishing the optical model essentially means matching the actual plane with the model plane. The optical model planes include the exposure plane and the detection plane, also known as the focus plane (FP) and the metrology plane (MP). Establishing an optical model that matches the actual process is crucial during the modeling process.

[0003] Currently, when establishing a lithography model, the critical dimensions obtained by optical model simulation are compared with the actual measured critical dimensions based on a certain number of mask patterns for different focus plane positions and metrology plane positions to obtain the line width difference. The root mean square (RMS) average of the line width differences corresponding to each mask pattern is then calculated. Ultimately, the focus plane position and metrology plane position corresponding to the minimum RMS average are used as parameters for establishing the lithography model. However, this method has limitations. For example, the measured values ​​are values ​​that have undergone the development process, while the simulated values ​​of the optical model are values ​​that have not undergone the development process. This may result in a smaller RMS average corresponding to the focus plane position and metrology plane position that are not fully matched, which may be mistakenly judged as the optimal optical model plane combination, resulting in increased modeling time and reduced modeling accuracy. Summary of the Invention

[0004] The embodiments of the present application provide a method, apparatus, device, medium and product for establishing a lithography model, which can determine accurate parameters for establishing the lithography model, thereby ensuring the accuracy and efficiency of the lithography modeling.

[0005] On the one hand, an embodiment of the present application provides a method for establishing a lithography model, comprising:

[0006] Determining an optimal preset focus plane position and an optimal preset metrology plane position based on a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position;

[0007] determining a focus plane position interval based on the optimal preset focus plane position;

[0008] At the optimal preset metrology plane position, respectively obtaining offset information between the actual critical dimension and the simulated critical dimension corresponding to each of the target mask patterns at each focus plane position within the focus plane position interval;

[0009] Based on the offset information, compensating the optimal preset focus plane position to obtain a target focus plane position;

[0010] Determining a target metrology plane position based on the target focus plane position and a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset metrology plane position;

[0011] The lithography model is established based on the target focus plane position and the target metrology plane position.

[0012] On the other hand, obtaining the offset information between the actual critical dimension and the simulated critical dimension corresponding to each of the target mask patterns at each focus plane position within the focus plane position interval at the optimal preset metrology plane position includes:

[0013] At the optimal preset metrology plane position, respectively obtaining an actual fitting curve and a simulation fitting curve corresponding to each of the target mask patterns; the actual fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding actual critical dimension, and the simulation fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding simulation critical dimension;

[0014] For each target mask pattern, the offset information between the corresponding actual fitting curve and the simulation fitting curve is obtained.

[0015] On the other hand, for each target mask pattern, obtaining the offset information between the corresponding actual fitting curve and the simulation fitting curve includes:

[0016] For each target mask pattern, determining the extreme point of the actual fitting curve as a first extreme point, and determining the extreme point of the simulation fitting curve as a second extreme point;

[0017] The offset distance between the first extreme point and the second extreme point is determined as the offset information for each target mask pattern.

[0018] On the other hand, compensating the optimal preset focus plane position based on the offset information to obtain a target focus plane position includes:

[0019] Taking a weighted average of the offset distances corresponding to the target mask patterns to obtain a target offset distance;

[0020] The optimal preset focus plane position is compensated based on the target offset distance to obtain a target focus plane position.

[0021] On the other hand, before performing weighted averaging on the offset distances corresponding to the target mask patterns to obtain the target offset distance, the method further includes:

[0022] Filtering out the offset distances exceeding a preset threshold from the offset distances corresponding to the target mask patterns to obtain the remaining offset distances;

[0023] The step of performing weighted averaging on the offset distances corresponding to the target mask patterns to obtain the target offset distance includes:

[0024] The remaining offset distances are weighted averaged to obtain the target offset distance.

[0025] On the other hand, determining the optimal preset focus plane position and the optimal preset metrology plane position based on the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position includes:

[0026] For each combination of the preset focus plane position and the preset metrology plane position, the following operations are performed: determining a first root mean square average value of line width differences corresponding to each target mask pattern at the corresponding preset focus plane position and the preset metrology plane position;

[0027] Among various combinations of the preset focus plane positions and the preset metrology plane positions, a combination corresponding to the smallest first root mean square average value is selected to determine as the optimal preset focus plane position and the optimal preset metrology plane position.

[0028] On the other hand, determining a target metrology plane position based on the target focus plane position and the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at each preset metrology plane position includes:

[0029] For each combination of the target focus plane position and each of the preset metrology plane positions, the following operations are performed: determining a second root mean square average value of line width differences corresponding to each of the target mask patterns at the target focus plane position and the corresponding preset metrology plane position;

[0030] Among various combinations of the target focus plane position and the preset metrology plane positions, a combination corresponding to the smallest second root mean square average value is selected to determine as the target metrology plane position.

[0031] In another aspect, an embodiment of the present application provides a device for establishing a lithography model, comprising: a processor and a memory storing computer program instructions;

[0032] When the processor executes the computer program instructions, the method for establishing the lithography model as described above is implemented.

[0033] On the other hand, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the method for establishing a lithography model as described above is implemented.

[0034] On the other hand, an embodiment of the present application provides a computer program product. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for establishing a lithography model as described above.

[0035] The embodiment of the present application provides a method for establishing a lithography model. Based on the difference between the simulated critical dimension and the actual critical dimension of the target mask pattern, two optimal preset plane positions are determined. Then, the offset information between the actual critical dimension and the simulated critical dimension corresponding to each target mask pattern at each focus plane position within the focus plane position interval is obtained respectively. Based on the offset information, the optimal preset focus plane position is compensated. Further, the target metrology plane position is determined based on the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at the target focus plane position and each preset metrology plane position. Finally, a lithography model is established based on the target focus plane position and the target metrology plane position. The solution proposed in this embodiment eliminates the error between the actual physical exposure and the model simulation by determining the offset information and compensating for the optimal preset focus plane. Then, the optimal metrology plane position is re-determined, so that accurate establishment parameters of the lithography model can be obtained, ensuring the accuracy and efficiency of lithography modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] Figure 1 A schematic diagram showing a flow chart of a method for establishing a lithography model provided by one embodiment of the present application is shown;

[0038] Figure 2 1 is a schematic diagram showing a comparison between an actual fitting curve and a simulation fitting curve;

[0039] Figure 3 A schematic diagram of a quadratic curve whose fitting degree does not meet the requirements is shown;

[0040] Figure 4A schematic structural diagram of a device for establishing a lithography model provided in an embodiment of the present application is shown;

[0041] Figure 5 A schematic diagram of the hardware structure of a device for establishing a lithography model provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprise..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0044] With the continuous advancement of semiconductor processing technology, optical proximity correction (OPC) has become an essential step in improving yield. The accuracy of OPC is heavily dependent on the accuracy of the lithography model, which consists of two parts: the optical model and the etch model. The optical model is often highly physical, and the optical transfer process can be fully expressed numerically.

[0045] In the process of establishing the optical model, it is necessary to determine the target focusing plane position and target metrology plane position required for model establishment based on the actual critical dimensions and simulated critical dimensions corresponding to different focusing plane positions and metrology plane positions.

[0046] The critical dimension here typically refers to the width of the exposure line at a preset location on the actual exposure pattern. The preset location is not specifically limited and can be set according to actual needs. The focus plane position refers to the relative position of the exposure system's focus plane in the direction of the photoresist thickness during exposure. The measurement plane position refers to the relative position of the measurement plane in the direction of the photoresist thickness when measuring the critical dimension.

[0047] Traditionally, the plane position corresponding to the smallest difference between the actual critical dimension and the simulated critical dimension is directly used as the model establishment parameter. However, the results obtained by this method may not match the actual situation, resulting in low model accuracy.

[0048] In order to solve the problems of the traditional solution, the embodiments of the present application provide a method, device, equipment, medium and product for establishing a lithography model. The following first introduces the method for establishing a lithography model provided by the embodiments of the present application. Figure 1 FIG. 1 is a flow chart of a method for establishing a lithography model provided by an embodiment of the present application. Figure 1 As shown, the method includes the following steps:

[0049] S101: determining an optimal preset focus plane position and an optimal preset metrology plane position based on a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position.

[0050] In practical applications, the focus plane position and metrology plane position are important parameters of the lithography model. Therefore, accurately calculating the appropriate focus plane position and metrology plane position is particularly important when establishing the lithography model. Proper focus plane position and metrology plane position can ensure that the quality of the exposed pattern meets the requirements.

[0051] Before determining the target positions for the two planes, multiple preset focus plane positions and multiple preset metrology plane positions are pre-set, allowing for the selection of optimal combinations among these plane positions. For each combination of preset focus plane positions and preset metrology plane positions, the corresponding simulated critical dimension and actual critical dimension are obtained for each target mask pattern. The linewidth difference between the simulated critical dimension and the actual critical dimension for each target mask pattern is then determined. Consequently, multiple linewidth differences are obtained for each position combination. Based on these linewidth differences, the optimal position combination, i.e., the optimal preset focus plane position and the optimal preset metrology plane position, can be selected.

[0052] The specific method used in selecting the optimal position combination is not limited. The root mean square (RMS) average of the line width differences corresponding to each target mask pattern can be obtained. Each position combination of a preset focus plane position and a preset metrology plane position corresponds to a RMS average. This RMS average represents the difference between the actual value and the simulated value. Therefore, the position combination corresponding to the minimum RMS average among the position combinations can be selected as the optimal position combination.

[0053] S102: Determine a focus plane position interval based on the optimal preset focus plane position.

[0054] To ensure the optimal two plane positions, after determining the optimal preset focus plane position and the optimal preset metrology plane position, further compensation adjustments are required. To achieve this, a focus plane position range must be determined for the optimal preset focus plane position. For example, assuming the reference position is set to 0 and the position 10 nm to the right of the optimal preset focus plane position, the focus plane position range can be set to the range (9, 11) to the right of the reference position.

[0055] S103: Under the optimal preset metrology plane position, respectively obtain the offset information between the actual critical dimension and the simulated critical dimension corresponding to each target mask pattern at each focus plane position within the focus plane position interval.

[0056] First, the metrology plane position must be fixed, i.e., the optimal preset metrology plane position determined above. At this optimal preset metrology plane position, the following operations are performed for each target mask pattern: At each focus plane position within the focus plane position range, the offset information between the actual critical dimension and the simulated critical dimension is obtained.

[0057] S104: Compensating the optimal preset focus plane position based on the offset information to obtain a target focus plane position.

[0058] The offset information determined above represents the offset between the actual critical dimension and the simulated critical dimension. Based on the offset information, the above-mentioned optimal preset focus plane position can be compensated to obtain the compensated and adjusted target focus plane position.

[0059] Each target mask pattern corresponds to multiple focus plane offset information. This offset information typically represents the offset distance between the actual critical dimension and the simulated critical dimension. For each target mask pattern, a representative target offset distance can be obtained by averaging the multiple offset distances. The optimal preset focus plane position is then compensated based on this target offset distance, for example by adding or subtracting the two to compensate for the difference between the simulated and actual values, ultimately yielding the target focus plane position.

[0060] S105: Determine a target metrology plane position based on the target focus plane position and the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at each preset metrology plane position.

[0061] At this point, the focus plane position is fixed, i.e., the target focus plane position determined above. Then, different preset metrology plane positions are used to obtain the simulated critical dimensions and actual critical dimensions of each target mask pattern. Finally, for each target mask pattern, the line width difference between the corresponding simulated critical dimension and the actual critical dimension is obtained.

[0062] During the specific calculation, for one of the preset measurement plane positions, the line width difference corresponding to each target mask pattern is obtained, and the root mean square average of these line width differences can also be calculated. Then, each preset measurement plane position corresponds to a root mean square average; the preset measurement plane position corresponding to the minimum root mean square average can be selected as the target measurement plane position.

[0063] S106: Establishing a lithography model based on the target focus plane position and the target metrology plane position.

[0064] Finally, based on the target focus plane position and target metrology plane position determined above, the required lithography model can be established.

[0065] The embodiment of the present application provides a method for establishing a lithography model. Based on the difference between the simulated critical dimension and the actual critical dimension of the target mask pattern, two optimal preset plane positions are determined. Then, the offset information between the actual critical dimension and the simulated critical dimension corresponding to each target mask pattern at each focus plane position within the focus plane position interval is obtained respectively. Based on the offset information, the optimal preset focus plane position is compensated. Further, the target metrology plane position is determined based on the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at the target focus plane position and each preset metrology plane position. Finally, a lithography model is established based on the target focus plane position and the target metrology plane position. The solution proposed in this embodiment eliminates the error between the actual physical exposure and the model simulation by determining the offset information and compensating for the optimal preset focus plane. Then, the optimal metrology plane position is re-determined, so that accurate establishment parameters of the lithography model can be obtained, ensuring the accuracy and efficiency of lithography modeling.

[0066] The purpose of determining offset information is to compensate for the discrepancy between actual and simulated values. The resulting offset information is used to compensate for the optimal preset focus plane position. Therefore, the metrology plane position must be fixed and then varied. Specifically, the optimal preset metrology plane position is set, and multiple focus plane positions are selected within the focus plane position range. Specifically, at the optimal preset metrology plane position, the actual and simulated fit curves corresponding to each target mask pattern are obtained. For each target mask pattern, the offset information between the corresponding actual and simulated fit curves is obtained.

[0067] When performing curve fitting, a quadratic curve is typically used. That is, both the actual fitting curve and the simulated fitting curve are quadratic curves. The actual fitting curve is a fitting curve that plots each focus plane position within the focus plane position interval against the corresponding actual critical dimension, while the simulated fitting curve is a fitting curve that plots each focus plane position within the focus plane position interval against the corresponding simulated critical dimension. For example, in a specific implementation, the following curve fitting method can be used: both the actual fitting curve and the simulated fitting curve use each focus plane position within the focus plane position interval as the horizontal coordinate, the actual critical dimension as the vertical coordinate of the actual fitting curve, and the simulated critical dimension as the coordinate of the simulated critical dimension.

[0068] The embodiment of the present application can quickly and accurately find the offset information between multiple actual critical dimensions and multiple simulated critical dimensions of the target mask pattern by fitting the curve.

[0069] The offset information here mainly represents the degree of offset between the two fitted curves. As mentioned above, quadratic curves are usually used for fitting. Therefore, if both curves have one and only one extreme point, the offset can be represented by the offset distance between the extreme points corresponding to the two fitted curves.

[0070] Specifically, for each target mask pattern, the extreme point of the actual fitting curve can be determined as the first extreme point, and the extreme point of the simulated fitting curve can be determined as the second extreme point; and the offset distance between the focus plane position corresponding to the first extreme point and the focus plane position corresponding to the second extreme point can be determined as the offset information for each target mask pattern.

[0071] Figure 2 FIG. 1 is a schematic diagram showing a comparison between an actual fitting curve and a simulation fitting curve; FIG. Figure 2 As shown, the focus plane position corresponding to the extreme point of the fitting curve corresponding to the calculated simulation key dimension is 2.67nm, the focus plane position corresponding to the extreme point of the fitting curve corresponding to the actual key dimension is 6.75nm, and the corresponding offset distance is 4.08nm.

[0072] In the embodiment of the present application, the extreme points of the two fitting curves corresponding to each target mask pattern are taken, and the distance between the focusing plane positions corresponding to the two extreme points is used as the offset information to compensate for the optimal focusing plane position, which can better eliminate the accidental influence in the model establishment process.

[0073] In the above embodiment, the offset information is specifically the offset distance between the focus plane positions corresponding to the extreme points of the two fitting curves, and each target mask pattern corresponds to an offset distance. Therefore, when performing compensation, these offset distances can be processed to obtain a specific representative value to achieve compensation for the optimal preset focus plane position.

[0074] Specifically, the offset distances corresponding to the target mask patterns can be weighted averaged to obtain the target offset distance. The optimal preset focus plane position can then be compensated based on the target offset distance to obtain the target focus plane position. The specific compensation method can be to add or subtract the target offset distance from the optimal preset focus plane position.

[0075] In the embodiment of the present application, a more representative target offset distance is obtained by performing a weighted average on the offset distances, so as to achieve more accurate compensation for the optimal preset focus plane position.

[0076] In addition, in the above embodiment, when performing weighted averaging on the offset distances corresponding to the target mask patterns, abnormal offset distances may cause errors in the calculation of subsequent steps. Therefore, these abnormal offset distances can be screened out in advance, and then calculations can be performed based on the remaining offset distances.

[0077] Specifically, the offset distances exceeding a preset threshold may be filtered out from the offset distances corresponding to the target mask patterns to obtain the remaining offset distances; and then the remaining offset distances are weighted averaged to obtain the target offset distance.

[0078] This embodiment filters out some excessively large offset distances to prevent abnormal data from affecting subsequent calculation results.

[0079] In a specific implementation, each target mask pattern corresponds to a line width difference value at each combination of the preset focus plane position and the preset metrology plane position. Therefore, for each combination of the preset focus plane position and the preset metrology plane position, the following operation can be performed: a first root mean square average value of the line width differences corresponding to the target mask patterns at the corresponding preset focus plane position and the preset metrology plane position is determined.

[0080] The calculation formula of the root mean square average RMS is as follows:

[0081]

[0082] Where x is the target line width difference, and n is the number of target mask patterns.

[0083] Then, among various combinations of the preset focus plane positions and the preset metrology plane positions, a combination corresponding to the smallest first root mean square average value is selected to determine the optimal preset focus plane position and the optimal preset metrology plane position.

[0084] In the embodiment of the present application, the first RMS average values ​​are calculated for different position combinations, and the position combination corresponding to the minimum value is selected as the optimal preset focus plane position and the optimal preset measurement plane position, thereby ensuring that the selected positions are more practical.

[0085] In the process of determining the target metrology plane position, the same can be achieved based on the root mean square average value. That is, for each combination of the target focus plane position and each preset metrology plane position, the following operations are performed: the second root mean square average value of the line width differences corresponding to each target mask pattern at the target focus plane position and the corresponding preset metrology plane position is determined; the calculation of the second root mean square average value can refer to formula (1).

[0086] Then, among various combinations of the target focus plane position and the preset metrology plane positions, a combination corresponding to the smallest second root mean square average value is selected to determine the target metrology plane position.

[0087] In the embodiment of the present application, the second RMS average values ​​are calculated for different position combinations respectively, and then the position combination corresponding to the minimum value is selected to determine the target measurement plane position, thereby ensuring that the selected position is more realistic.

[0088] In addition, in actual applications, some data preparation work needs to be done before implementing the above solution, as follows:

[0089] Step 1: Set the input parameters of the optical model, including light source, mask, and polarization. The light source includes information such as wavelength, light source shape, and alignment; the mask includes the target mask pattern and mask type.

[0090] Step 2: Screen the gauge file and determine the input gauge (ie, select the target mask pattern from a large number of preset mask patterns).

[0091] Because there are usually a large number of preset mask patterns in actual applications, and only some of these preset mask patterns meet the modeling requirements, these preset mask patterns can be screened to obtain the target mask pattern. Figure 3 A schematic diagram of a quadratic curve whose fitting degree does not meet the requirements is shown; Figure 3 As shown in the figure, by determining whether the actual critical dimensions (ordinate) under different focus plane positions (abscissa) conform to the quadratic distribution, the gauge with the best quadratic fitting effect can be selected as input in each set of data. Specifically, the fitting metric value R of the quadratic fitting curve can be 2 As a screening indicator.

[0092] Step 3: Determine the depth range of the optical plane based on the exposed film structure, generally 0 to resist thickness (resist thickness is the thickness of the photoresist).

[0093] In order to solve the above technical problems, the present invention also provides a device for establishing a lithography model. Figure 4 FIG. 1 shows a schematic diagram of the structure of the device for establishing the lithography model provided in an embodiment of the present application. Figure 4 As shown, the device includes the following modules:

[0094] A first determining module 401 is configured to determine an optimal preset focus plane position and an optimal preset metrology plane position based on a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position;

[0095] A second determining module 402 is configured to determine a focus plane position interval based on an optimal preset focus plane position;

[0096] The first acquisition module 403 is configured to acquire, at the optimal preset metrology plane position, offset information between the actual critical dimension and the simulated critical dimension corresponding to each target mask pattern at each focus plane position within the focus plane position interval;

[0097] A compensation module 404 is configured to compensate the optimal preset focus plane position based on the offset information to obtain a target focus plane position;

[0098] A third determining module 405 is configured to determine a target metrology plane position based on the target focus plane position and the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at each preset metrology plane position;

[0099] The establishing module 406 is configured to establish a lithography model based on the target focus plane position and the target metrology plane position.

[0100] In some embodiments, the first acquisition module is specifically configured to:

[0101] Under the optimal preset metrology plane position, the actual fitting curve and the simulation fitting curve corresponding to each target mask pattern are respectively obtained; the actual fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding actual critical dimension, and the simulation fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding simulated critical dimension;

[0102] For each target mask pattern, the offset information between the corresponding actual fitting curve and the simulation fitting curve is obtained.

[0103] In some embodiments, the first acquisition module is specifically configured to:

[0104] For each target mask pattern, the extreme point of the actual fitting curve is determined as the first extreme point, and the extreme point of the simulated fitting curve is determined as the second extreme point;

[0105] The offset distance between the focus plane position corresponding to the first extreme point and the focus plane position corresponding to the second extreme point is determined as the offset information for each target mask pattern.

[0106] In some embodiments, the compensation module is specifically configured to:

[0107] The target offset distance is obtained by weighted averaging the offset distances corresponding to the target mask patterns.

[0108] The optimal preset focus plane position is compensated based on the target offset distance to obtain the target focus plane position.

[0109] In some embodiments, the establishing device of the lithography model further comprises a filtering module configured to filter out the offset distances exceeding the preset threshold from the offset distances corresponding to each target mask pattern, to obtain the residual offset distances, before performing the weighted average of the offset distances corresponding to each target mask pattern to obtain the target offset distance.

[0110] The computing module is configured to perform the weighted average of the offset distances corresponding to each target mask pattern to obtain the target offset distance, comprising:

[0111] performing the weighted average of the residual offset distances to obtain the target offset distance.

[0112] In some embodiments, the first determining module is specifically configured to:

[0113] For each combination of each preset focus plane position and each preset metrology plane position, the following operation is performed: determining a first root mean square average value between the line width difference values corresponding to each target mask pattern under the corresponding preset focus plane position and preset metrology plane position.

[0114] In the various combinations of each preset focus plane position and each preset metrology plane position, the combination corresponding to the minimum first root mean square average value is selected to determine the optimal preset focus plane position and the optimal preset metrology plane position.

[0115] In some embodiments, the second determining module is specifically configured to:

[0116] For each combination of the target focus plane position and each preset metrology plane position, the following operation is performed: determining a second root mean square average value between the line width difference values corresponding to each target mask pattern under the target focus plane position and the corresponding preset metrology plane position.

[0117] In the various combinations of the target focus plane position and each preset metrology plane position, the combination corresponding to the minimum second root mean square average value is selected to determine the target metrology plane position.

[0118] The device provided by the embodiments of the present application is the same as the method in the above-mentioned embodiments, so both have the same embodiments and beneficial effects, which will not be repeated here.

[0119] Figure 5 A hardware structure schematic diagram of the establishing device of the lithography model provided by the embodiments of the present application is shown. As shown in the figure, Figure 5 The establishing device of the lithography model can include a processor 501 and a memory 502 storing computer program instructions.

[0120] Specifically, the processor 501 can include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or can be configured to implement one or more integrated circuits that embody the embodiments of the present application.

[0121] The memory 502 can include mass storage for data or instructions. By way of example, and not limitation, the memory 502 can include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disc (e.g., a CD or DVD), a tape drive, a USB drive, or a combination of two or more of these. The memory 502 can be removable and / or non-removable (or fixed) as appropriate. The memory 502 can be internal or external as appropriate. In certain embodiments, the memory 502 is non-volatile solid-state memory.

[0122] The memory 502 can include read-only memory (ROM), random access memory (RAM), magnetic disk storage mediums, optical storage mediums, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software that, when executed (by one or more processors), is operable to perform operations described with reference to the methods according to an aspect of the present disclosure.

[0123] The processor 501 implements the method for establishing a lithography model in any of the above embodiments by reading and executing computer program instructions stored in the memory 502.

[0124] In one example, the device for establishing a lithography model can further include a communication interface 503 and a bus 504. The processor 501, the memory 502, and the communication interface 503 are connected through the bus 504 and complete communication with each other.

[0125] The communication interface 503 is mainly used to realize the communication between the modules, devices, units and / or equipment in the embodiments of the present application.

[0126] Bus 504 includes a hardware, software, or both, that couples components of the lithography model building device to each other. As an example but not a limitation, the bus can include an Accelerate Graphical Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or another suitable bus or a combination of two or more of these. Where appropriate, bus 504 can include one or more buses. Although this application describes and shows a particular bus, this application contemplates any suitable bus or interconnect.

[0127] In addition, in combination with the method for building a lithography model in the above embodiments, the embodiments of the present application can provide a computer storage medium for implementation. The computer storage medium has computer program instructions stored thereon; the computer program instructions are executed by a processor to implement any of the above-mentioned methods for building a lithography model.

[0128] The embodiments of the present application also provide a computer program product, including a computer program, which is executed by a processor to implement any of the above-mentioned methods for building a lithography model.

[0129] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0130] The functional blocks shown in the block diagram above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, ASICs, appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or communication link via a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (Erasable ROM, EROMs), floppy disks, compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROMs), optical discs, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0131] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0132] The above describes various aspects of the present disclosure with reference to the flowcharts and / or block diagrams of a method, apparatus, device, medium, and product for establishing a lithography model according to an embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of boxes in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes in the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by special-purpose hardware that performs the specified function or action, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0133] The above content is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. A method for establishing a lithography model, characterized in that: include: Determining an optimal preset focus plane position and an optimal preset metrology plane position based on a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position; determining a focus plane position interval based on the optimal preset focus plane position; At the optimal preset metrology plane position, respectively obtaining offset information between the actual critical dimension and the simulated critical dimension corresponding to each of the target mask patterns at each focus plane position within the focus plane position interval; Based on the offset information, compensating the optimal preset focus plane position to obtain a target focus plane position; Determining a target metrology plane position based on the target focus plane position and a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset metrology plane position; The lithography model is established based on the target focus plane position and the target metrology plane position.

2. The method for establishing a lithography model according to claim 1, wherein: The step of obtaining, at the optimal preset metrology plane position, offset information between actual critical dimensions and simulated critical dimensions corresponding to each of the target mask patterns at each focus plane position within the focus plane position interval includes: At the optimal preset metrology plane position, respectively obtaining an actual fitting curve and a simulation fitting curve corresponding to each of the target mask patterns; the actual fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding actual critical dimension, and the simulation fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding simulation critical dimension; For each target mask pattern, the offset information between the corresponding actual fitting curve and the simulation fitting curve is obtained.

3. The method for establishing a lithography model according to claim 2, wherein: For each target mask pattern, obtaining the offset information between the corresponding actual fitting curve and the simulation fitting curve includes: For each target mask pattern, determining the extreme point of the actual fitting curve as a first extreme point, and determining the extreme point of the simulation fitting curve as a second extreme point; An offset distance between a focus plane position corresponding to the first extreme point and a focus plane position corresponding to the second extreme point is determined as the offset information for each target mask pattern.

4. The method for establishing a lithography model according to claim 3, wherein: The compensating the optimal preset focus plane position based on the offset information to obtain a target focus plane position includes: Taking a weighted average of the offset distances corresponding to the target mask patterns to obtain a target offset distance; The optimal preset focus plane position is compensated based on the target offset distance to obtain a target focus plane position.

5. The method for establishing a lithography model according to claim 4, wherein: Before performing weighted averaging on the offset distances corresponding to the target mask patterns to obtain the target offset distance, the method further includes: Filtering out the offset distances exceeding a preset threshold from the offset distances corresponding to the target mask patterns to obtain the remaining offset distances; The step of performing weighted averaging on the offset distances corresponding to the target mask patterns to obtain the target offset distance includes: The remaining offset distances are weighted averaged to obtain the target offset distance.

6. The method for establishing a lithography model according to any one of claims 1 to 5, characterized in that: The determining of the optimal preset focus plane position and the optimal preset metrology plane position based on the line width difference between the simulated critical dimension and the actual critical dimension of each target mask pattern at each preset focus plane position and each preset metrology plane position includes: For each combination of the preset focus plane position and the preset metrology plane position, the following operations are performed: determining a first root mean square average value of line width differences corresponding to each target mask pattern at the corresponding preset focus plane position and the preset metrology plane position; Among various combinations of the preset focus plane positions and the preset metrology plane positions, a combination corresponding to the smallest first root mean square average value is selected to determine the optimal preset focus plane position and the optimal preset metrology plane position.

7. The method for establishing a lithography model according to claim 6, wherein: Determining a target metrology plane position based on the target focus plane position and a line width difference between a simulated critical dimension and an actual critical dimension of each target mask pattern at each preset metrology plane position includes: For each combination of the target focus plane position and each of the preset metrology plane positions, the following operations are performed: determining a second root mean square average value of line width differences corresponding to each of the target mask patterns at the target focus plane position and the corresponding preset metrology plane position; Among various combinations of the target focus plane position and each of the preset metrology plane positions, a combination corresponding to the smallest second root mean square average value is selected to determine the target metrology plane position.

8. A device for establishing a lithography model, characterized in that: include: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the method for establishing a lithography model according to any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the method for establishing a lithography model according to any one of claims 1 to 7 is implemented.

10. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for establishing a lithography model according to any one of claims 1 to 7.

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