Method, device and equipment for establishing photoetching model, medium and product

Abstract

The invention discloses a photoetching model establishing method, device and equipment, a medium and a product, and is applied to the technical field of photoetching. The method comprises the following steps: firstly, presetting two optimal plane positions; and then compensating the optimal preset focusing plane position based on the offset information between the actual key size and the simulation key size. Further determining the position of a target metering plane based on the line width difference value; and finally, based on the target focusing plane position and the target metering plane position, establishing a photoetching model. According to the scheme provided by the embodiment of the invention, the error between actual physical exposure and model simulation is eliminated by determining the offset information and compensating the optimal preset focusing plane, and the optimal measurement plane position is further determined again, so that accurate establishment parameters of the photoetching model can be obtained, and the accuracy and efficiency of photoetching modeling are ensured.

Description

Technical Field

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

[0002] The photolithography model consists of two parts: the optical model and the etching model. The establishment of the optical model is actually to achieve the matching of the actual plane and the model plane. The optical model plane includes the exposure plane and the detection plane, also known as the focus plane (FP) and the metrology plane (MP). It is very important to establish an optical model that matches the actual process in the modeling process.

[0003] At present, when establishing a lithography model, for different focal plane positions and metrology plane positions, based on a certain number of mask patterns, the key dimensions obtained by optical model simulation are compared with the key dimensions actually measured to obtain the line width difference, and then the root mean square average RMS of the line width difference corresponding to each mask pattern is calculated. Finally, the focal plane position and metrology plane position corresponding to the minimum root mean square average value are used as the parameters for establishing the lithography model. However, this method has limitations. For example, the measured value is the value after the development process, while the simulated value of the optical model is the value without the development process. This may result in a smaller root mean square average corresponding to the focal plane position and metrology plane position that are not fully matched, which may be misjudged as the optimal optical model plane combination, which in turn increases the modeling time and reduces the modeling accuracy. Summary of the invention

[0004] The embodiments of the present application provide a method, device, equipment, 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] Determine an optimal preset focusing 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 focusing plane position and each preset metrology plane position;

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

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

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

[0012] On the other hand, the step of 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] Under the optimal preset metrology plane position, respectively obtain 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 of the target mask patterns, the offset information between the corresponding actual fitting curve and the simulation fitting curve is obtained.

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

[0016] For each of the target mask patterns, 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 of the target mask patterns.

[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 comprises:

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

[0025] On the other hand, 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:

[0026] For each combination of each of the preset focus plane positions and each of the preset metrology plane positions, the following operations are performed: determining a first root mean square average value between line width differences corresponding to each of the target mask patterns 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, based on the target focus plane position and the line width difference between the simulated critical dimension and the actual critical dimension of each of the target mask patterns at each of the preset metrology plane positions, determining the target 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 between 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 each of 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, on which computer program instructions are stored. 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, which determines two optimal preset plane positions based on the difference between the simulated critical dimension and the actual critical dimension of the target mask pattern; then obtains 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; and compensates for the optimal preset focus plane position based on the offset information. 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, the lithography model is established based on the target focus plane position and the target metrology plane position. The scheme 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, and further re-determines the optimal metrology plane position, so that the 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 solution 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 of a process of establishing a lithography model provided by an 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 diagram of the structure 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 lithography model building device 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 only 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 "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "include..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0044] With the continuous improvement of semiconductor technology, optical proximity correction has become an essential part of improving yield. The accuracy of optical proximity correction is heavily dependent on the accuracy of the lithography model, which consists of two parts: the optical model and the etching model. The optical model is often very 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 establishing the model based on the actual key dimensions and simulated key dimensions corresponding to different focusing plane positions and metrology plane positions.

[0046] The critical dimension here usually refers to the width of the exposure line at the preset position on the actual exposure pattern. The preset position is not specifically limited and can be set according to actual needs. The focus plane position refers to the relative position of the focus plane of the exposure system in the direction of the photoresist thickness when the lithography machine is exposed. 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] In the traditional solution, the plane position corresponding to the smaller difference between the actual key dimension and the simulated key 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 embodiment of the present application provides a method, device, equipment, medium and product for establishing a lithography model. The method for establishing a lithography model provided by the embodiment of the present application is first introduced below. 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 comprises 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 the 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 in the process of establishing the lithography model. Reasonable focus plane position and metrology plane position can ensure that the quality of the exposure pattern meets the requirements.

[0051] Before determining the target positions of the two planes, multiple preset focus plane positions and multiple preset metrology plane positions are pre-set to select a better combination among these plane positions. Under one of the combinations of preset focus plane positions and preset metrology plane positions, the corresponding simulation critical dimensions and actual critical dimensions can be obtained for each target mask pattern; then the line width difference between the simulation critical dimensions and the actual critical dimensions corresponding to each target mask pattern is obtained. Therefore, multiple line width differences can be obtained under each position combination, and based on these line width differences, the best position combination, that is, the best preset focus plane position and the best preset metrology plane position, can be selected.

[0052] In the process of selecting the best position combination, the specific method used is not limited. The root mean square average value of the line width difference corresponding to each target mask pattern can be obtained, and each position combination of the preset focus plane position and the preset measurement plane position corresponds to a root mean square average value; this root mean square average value represents the difference between the actual value and the simulation value, so the position combination corresponding to the minimum root mean square average value can be selected from each position combination as the best position combination.

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

[0054] In order to ensure that the two optimal plane positions are finally obtained, after determining the optimal preset focus plane position and the optimal preset measurement plane position, it is necessary to further compensate and adjust the two plane positions. In the meantime, it is necessary to first determine a focus plane position interval for the optimal preset focus plane position. For example, assuming that the reference position is preset to 0 and the position 10nm to the right is the optimal preset focus plane position, the interval (9,11) to the right of the reference position can be taken as the focus plane position interval.

[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 under each focus plane position within the focus plane position interval.

[0056] Here, the metrology plane position needs to be fixed first, that is, the optimal preset metrology plane position determined above is taken. At the 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 interval, the offset information between the actual critical dimension and the simulated critical dimension is obtained respectively.

[0057] S104: Based on the offset information, the optimal preset focus plane position is compensated 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 offset information of the focus plane position, and the offset information is generally the offset distance between the actual key size and the simulated key size. For multiple offset distances corresponding to a target mask pattern, the final representative target offset distance can be obtained by taking the average value, etc. Then, the optimal preset focus plane position is compensated based on this target offset distance, for example, the two are added or subtracted to make up for the difference between the simulated value and the actual value, and finally the target focus plane position is obtained.

[0060] S105: Determine the 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 can be fixed, that is, the target focus plane position determined above. Then, different preset metrology plane positions are taken, and the simulated critical dimensions and actual critical dimensions of each target mask pattern are obtained, and then for each target mask pattern, the line width difference between the corresponding simulated critical dimensions and the actual critical dimensions is obtained.

[0062] During specific calculations, 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 the 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, which determines two optimal preset plane positions based on the difference between the simulated critical dimension and the actual critical dimension of the target mask pattern; then obtains 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; and compensates for the optimal preset focus plane position based on the offset information. 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, the lithography model is established based on the target focus plane position and the target metrology plane position. The scheme 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, and further re-determines the optimal metrology plane position, so that the accurate establishment parameters of the lithography model can be obtained, ensuring the accuracy and efficiency of lithography modeling.

[0066] The purpose of determining the offset information is to make up for the difference between the actual value and the simulated value. The final offset information is to compensate for the optimal preset focus plane position. Therefore, it is necessary to first fix the metrology plane position and then change the focus plane position, that is, set it to the optimal preset metrology plane position, and take multiple focus plane positions within the focus plane position interval. Specifically, under the optimal preset metrology plane position, the actual fitting curve and the simulation fitting curve corresponding to each target mask pattern are obtained respectively. For each target mask pattern, the offset information between the corresponding actual fitting curve and the simulation fitting curve is obtained.

[0067] When performing curve fitting, a quadratic curve is usually used for fitting, that is, both the actual fitting curve and the simulation fitting curve are quadratic curves. The actual fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding actual key size, and the simulation fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding simulation key size. For example, in a specific implementation, the following method can be used to fit the curve: both the actual fitting curve and the simulation fitting curve use each focus plane position within the focus plane position interval as the horizontal coordinate, the actual key size as the vertical coordinate of the actual fitting curve, and the simulation key size as the coordinate of the simulation key size.

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

[0069] The offset information here mainly represents the offset between the two fitting curves. As mentioned above, quadratic curves are usually used for fitting, so both curves have and only have one extreme point, and the offset can be represented by the offset distance between the extreme points corresponding to the two fitting 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; 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] The embodiment of the present application takes the extreme points of the two fitting curves corresponding to each target mask pattern, and uses the distance between the focusing plane positions corresponding to the two extreme points as offset information to compensate for the optimal focusing plane position, which can better eliminate the accidental influence in the model building process.

[0073] In the above embodiment, it is mentioned that 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. 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 may be weighted averaged to obtain the target offset distance, and then the optimal preset focus plane position may be compensated based on the target offset distance to obtain the target focus plane position. The specific compensation method may be to increase or subtract the target offset distance based on the optimal preset focus plane position.

[0075] The embodiment of the present application obtains a more representative target offset distance by performing weighted averaging 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 weighted averaging the offset distances corresponding to the target mask patterns, abnormal offset distances may cause errors in calculations in subsequent steps. Therefore, these abnormal offset distances can be screened out in advance, and then calculations are performed based on the remaining offset distances.

[0077] Specifically, the offset distances exceeding a preset threshold value 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 prevents abnormal data from affecting subsequent calculation results by filtering out some excessively large offset distances.

[0079] In a specific implementation, under each combination of the preset focusing plane position and the preset measurement plane position, each target mask pattern corresponds to a line width difference. Then, for each combination of each preset focusing plane position and each preset measurement plane position, the following operations can be performed: determine the first root mean square average value between the line width differences corresponding to each target mask pattern under the corresponding preset focusing plane position and the preset measurement plane position.

[0080] The calculation formula of the root mean square average value 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 preset focus plane positions and preset metrology plane positions, a combination corresponding to the smallest first root mean square average value is selected to determine the best preset focus plane position and the best preset metrology plane position.

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

[0085] In the process of determining the target metrology plane position, it can also be implemented 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 between the line width differences corresponding to each target mask pattern under 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 each preset metrology plane position, 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 practical 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 graphics in practical applications, and only some of these preset mask graphics meet the modeling requirements, these preset mask graphics can be screened to obtain the target mask graphics. 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 (horizontal coordinates) 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 according to 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 application also provides a device for establishing a lithography model. Figure 4 FIG. 1 is a schematic diagram showing the structure of a device for establishing a lithography model provided in an embodiment of the present application. Figure 4 As shown, the device includes the following modules:

[0094] A first determination module 401 is used 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 determination module 402, configured to determine a focus plane position interval based on an optimal preset focus plane position;

[0096] The first acquisition module 403 is used to respectively acquire 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 at the optimal preset metrology plane position;

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

[0098] A third determination module 405 is used to determine the 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 used 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 best preset metrology plane position, respectively obtain the actual fitting curve and the simulation fitting curve corresponding to each target mask pattern; the actual fitting curve is a fitting curve between each focus plane position within the focus plane position interval and the corresponding actual key 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 key 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 offset distances corresponding to the target mask patterns are weighted averaged to obtain the target offset distance;

[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 apparatus for establishing a lithography model further includes: a filtering module for filtering out the offset distances exceeding a preset threshold from the offset distances corresponding to the target mask patterns before performing weighted averaging on the offset distances corresponding to the target mask patterns to obtain the target offset distances, so as to obtain the remaining offset distances;

[0110] The calculation module is used to perform weighted average of the offset distances corresponding to each target mask pattern to obtain the target offset distance, including:

[0111] The remaining offset distances are weighted averaged 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 operations are performed: determining a first root mean square average value between line width differences corresponding to each target mask pattern at the corresponding preset focus plane position and preset metrology plane position;

[0114] Among various combinations of preset focus plane positions and preset metrology plane positions, a combination corresponding to the smallest first root mean square average value is selected to determine an optimal preset focus plane position and an 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 operations are performed: determining a second root mean square average value between line width differences corresponding to each target mask pattern at the target focus plane position and the corresponding preset metrology plane position;

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

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

[0119] Figure 5 FIG. 1 is a schematic diagram showing the hardware structure of a device for establishing a lithography model provided in an embodiment of the present application. Figure 5 As shown, the device for establishing a lithography model may include a processor 501 and a memory 502 storing computer program instructions.

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

[0121] The memory 502 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 502 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 502 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 502 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 502 is a non-volatile solid-state memory.

[0122] The memory 502 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of the present disclosure.

[0123] The processor 501 reads and executes the computer program instructions stored in the memory 502 to implement any one of the photolithography model building methods in the above embodiments.

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

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

[0126] The bus 504 includes hardware, software, or both, coupling the components of the lithography model establishment device to each other. By way of example and not limitation, the bus may 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 other suitable buses or a combination of two or more of these. Where appropriate, the bus 504 may include one or more buses. Although embodiments of the present application describe and illustrate a particular bus, the present application contemplates any suitable bus or interconnect.

[0127] In addition, in combination with the method for establishing a lithography model in the above embodiments, the present application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the methods for establishing a lithography model in the above embodiments is implemented.

[0128] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed, implements any one of the methods for establishing a lithography model in the above embodiments.

[0129] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between 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, it can be, for example, an electronic circuit, an ASIC, appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments 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 a communication link by 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, ROM, flash memory, erasable ROM (Erasable ROM, EROM), floppy disks, compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), optical discs, hard disks, optical fiber media, radio frequency (Radio Frequency, RF) links, etc. 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, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0132] The above describes various aspects of the present disclosure with reference to the flowchart and / or block diagram of a method, device, equipment, 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 each box 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 of 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 dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0133] The above contents are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity 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 protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A method for establishing a lithography model, characterized in that: include: Determine an optimal preset focusing 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 focusing plane position and each preset metrology plane position; Determining a focus plane position interval based on the optimal preset focus plane position; Under the optimal preset metrology plane position, respectively obtaining the offset information between the actual critical dimension and the simulated critical dimension corresponding to each of the target mask patterns under 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; 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 of the target mask patterns at each of the preset metrology plane positions; 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, characterized in that: 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 comprises: Under the optimal preset metrology plane position, respectively obtain 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 of the target mask patterns, 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, characterized in that: For each of the target mask patterns, obtaining the offset information between the corresponding actual fitting curve and the simulation fitting curve includes: For each of the target mask patterns, 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; 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 of the target mask patterns.

4. The method for establishing a lithography model according to claim 3, characterized in that: 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, characterized in that: 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 comprises: 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 focusing 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 focusing plane position and each preset metrology plane position comprises: For each combination of each of the preset focus plane positions and each of the preset metrology plane positions, the following operations are performed: determining a first root mean square average value between line width differences corresponding to each of the target mask patterns 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, characterized in that: 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: 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 between 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 photolithography 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 as described in any one of claims 1 to 7.

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