Method, Device, Storage Medium, and Program Product for Light Source Mask Optimization

Abstract

Embodiments of the present disclosure provide a method, an apparatus, a storage medium, and a program product for light source mask optimization. The method includes receiving a set of mask patterns. The method further includes obtaining a plurality of light source patterns to be used as a plurality of initial light source patterns respectively, where the plurality of light source patterns are generated based on the set of mask patterns. The method further includes, for each combination of a light source mask pattern formed by each light source pattern among the plurality of light source patterns and the set of mask patterns, iteratively updating each light source pattern and the set of mask patterns in the light source mask pattern combination to obtain an iteratively updated light source mask pattern combination. The method further includes determining an optimized light source pattern and an optimized mask pattern based on a plurality of iteratively updated light source mask pattern combinations respectively corresponding to the plurality of light source patterns.

Description

Technical Field

[0001] Embodiments of the present disclosure mainly relate to integrated circuits, and more particularly, to methods, electronic devices, computer-readable storage media, and computer program products for light source mask optimization. Background Art

[0002] Lithography is a key process in the integrated circuit manufacturing process. The lithography process utilizes the principle of photochemical reaction and chemical and physical etching methods to transfer the pattern prepared on the mask onto the wafer. The lithography process can be described by optical and chemical models with the aid of mathematical formulas. Light diffracts when it shines on the mask, and the diffraction is collected by the projection lens and converges on the surface of the photoresist. This imaging process is an optical process. The image projected on the photoresist stimulates a photochemical reaction, and after baking, it causes the photoresist to be locally soluble in the developer. This is a chemical process.

[0003] With the continuous reduction of the semiconductor manufacturing process node, the minimum line width of the integrated circuit is much smaller than the light source wavelength of the lithography process. The diffraction effect of light restricts the resolution of lithography imaging, thereby leading to a reduction in the process window and a decrease in the yield. Therefore, resolution enhancement techniques are required in the lithography process.

[0004] As an important lithography resolution enhancement technique, source-mask optimization (SMO; or "light source mask optimization") can consider both the light source illumination pattern and the mask pattern simultaneously. By optimizing the distribution of the light source intensity and the mask pattern, the goal of expanding the lithography process window can be achieved. Therefore, the source-mask optimization technique is a key technology for improving lithography resolution and process window. Summary of the Invention

[0005] According to an exemplary embodiment of the present disclosure, a solution for light source mask optimization is provided.

[0006] In a first aspect of the present disclosure, a method for light source mask optimization is provided. The method includes receiving a set of mask patterns. The method includes obtaining a plurality of light source patterns to be used as a plurality of initial light source patterns respectively, where the plurality of light source patterns are generated based on the set of mask patterns. The method further includes, for each combination of a light source mask pattern formed by each light source pattern among the plurality of light source patterns and the set of mask patterns, iteratively updating each light source pattern and the set of mask patterns in the light source mask pattern combination to obtain an iteratively updated light source mask pattern combination. The method further includes determining an optimized light source pattern and an optimized mask pattern based on the plurality of iteratively updated light source mask pattern combinations respectively corresponding to the plurality of light source patterns.

[0007] In a second aspect of the present disclosure, an electronic device is provided. The electronic device includes one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, cause the electronic device to perform actions. The actions include: receiving a set of mask patterns; obtaining a plurality of light source patterns to be respectively used as a plurality of initial light source patterns, wherein the plurality of light source patterns are generated based on the set of mask patterns; for each combination of a light source mask pattern formed by each light source pattern among the plurality of light source patterns and the set of mask patterns, iteratively updating each light source pattern and the set of mask patterns in the light source mask pattern combination to obtain an iteratively updated light source mask pattern combination; and determining an optimized light source pattern and an optimized mask pattern based on the plurality of iteratively updated light source mask pattern combinations respectively corresponding to the plurality of light source patterns.

[0008] In a third aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method according to the first aspect of the present disclosure is implemented.

[0009] In a fourth aspect of the present disclosure, a computer program product is provided, which includes program code. When the program code is executed by a processor, the method according to the first aspect of the present disclosure is implemented.

[0010] It should be understood that the content described in the Summary of the Invention section is not intended to limit the key or important features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In combination with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements, where:

[0012] Figure 1 An exemplary environment in which the embodiments of the present disclosure can be implemented is shown;

[0013] Figure 2 A flowchart of an exemplary method for light source mask optimization according to some embodiments of the present disclosure is shown;

[0014] Figures 3A - 3D Schematic examples of 4 target mask patterns are respectively shown;

[0015] Figure 4 A flowchart of a gradient-based iterative optimization method according to an embodiment of the present disclosure is shown;

[0016] Figure 5A flowchart showing an example method of generating a plurality of light source patterns based on a set of mask patterns according to an embodiment of the present disclosure;

[0017] Figure 6 A flowchart showing an example method of determining a light source pattern corresponding to a target mask pattern based on the pattern information of the target mask pattern according to an embodiment of the present disclosure;

[0018] Figure 7 A schematic implementation process of blurring a real number matrix according to an embodiment of the present disclosure;

[0019] Figure 8 A schematic comparison diagram of an image obtained based on a real number matrix before blurring and an image obtained based on a real number matrix after blurring according to an embodiment of the present disclosure;

[0020] Figures 9A - 9C A schematic example diagram of three light source patterns determined according to an embodiment of the present disclosure;

[0021] Figure 9D A schematic example diagram of a light source pattern for dipole illumination; and

[0022] Figure 10 A block diagram of an electronic device capable of implementing the embodiments of the present disclosure is shown. Detailed Description of Specific Embodiments

[0023] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure.

[0024] In the description of the embodiments of the present disclosure, the term "including" and its like should be understood as an open inclusion, that is, "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. There may also be other explicit and implicit definitions hereinafter.

[0025] As briefly mentioned above, source-mask co-optimization or source-mask optimization is an important lithography resolution enhancement technique that aims to expand the lithography process window by optimizing the source intensity and the distribution of mask patterns. Typically, source-mask optimization requires evaluating the lithography imaging performance of different combinations of source patterns and mask patterns, and updating the source patterns and mask patterns based on the evaluation results. To accommodate mask patterns with various distributions, an annular light source or a dipole light source is usually selected as the initial source pattern to perform source-mask optimization. That is, with the annular light source pattern or the dipole light source as the initial source, the source pattern and the mask pattern are iteratively updated.

[0026] In existing source-mask optimization schemes, a single initial source is usually adopted to perform source-mask optimization for iterative updating of the source pattern and the mask pattern. However, the single initial source limits the convergence path of source-mask optimization and is not conducive to source-mask optimization getting out of the local optimal solution. In addition, the optimization result of source-mask optimization also has a large correlation with the initial source. In source-mask optimization technology, a parameterized single initial source is usually determined based on experience. For example, an annular light source or a dipole light source (such as the dipole illumination source shown in Figure 9D is usually selected as the initial source based on experience. However, the parameterized source determined based on experience has a large randomness, is difficult to accommodate multiple target mask patterns simultaneously, and has nothing to do with the imaging optical behavior of the target mask pattern, making it difficult to ensure that it is a good initial source.

[0027] To at least solve the above technical problems, according to an embodiment of the present disclosure, a method for source-mask optimization is proposed. The method includes receiving a set of mask patterns. The method further includes obtaining a plurality of source patterns to be used as a plurality of initial source patterns respectively, where the plurality of source patterns are generated based on the set of mask patterns. The method also includes, for each combination of a source mask pattern formed by each source pattern among the plurality of source patterns and the set of mask patterns, iteratively updating each source pattern and the set of mask patterns in the source mask pattern combination to obtain an iteratively updated source mask pattern combination. The method further includes determining an optimized source pattern and an optimized mask pattern based on the plurality of iteratively updated source mask pattern combinations respectively corresponding to the plurality of source patterns.

[0028] According to the solution for light source mask optimization proposed by the embodiments of the present disclosure, by using multiple initial light sources for optimization, a light source pattern and a mask pattern that meet the requirements can be selected from multiple sets of optimization results as the target optimization result. Thereby, the probability of the optimization falling into a local optimal solution can be reduced, and the probability of obtaining a more compliant optimization result can be increased. At the same time, according to the solution for light source mask optimization of the embodiments of the present disclosure, by generating multiple light source patterns as the initial light source patterns based on the optical diffraction characteristics of the target mask pattern, the initial light source patterns can be related to the imaging optical behavior of the target mask pattern, so that the generated initial light sources can have better imaging performance, and thus a significantly increased process window can be provided.

[0029] Figure 1 FIG. 100 shows an example environment in which multiple embodiments of the present disclosure can be implemented. As Figure 1 shown, the electronic device 120 can receive a set of mask patterns 110, where the set of mask patterns 110 includes multiple mask patterns, for example, the first mask pattern 110-1, the second mask pattern 110-2,..., the Nth mask pattern 110-N. The multiple mask patterns included in the set of mask patterns 110 input to the electronic device 120 can be respectively multiple target mask patterns, that is, the target patterns expected to be imaged on the wafer through the lithography process.

[0030] The electronic device 120 can also obtain multiple light source patterns (for example, the first light source pattern S1, the second light source pattern S2,..., the Jth light source pattern S J ) to be used as multiple initial light source patterns respectively. Among them, the multiple light source patterns (for example, the first light source pattern S1, the second light source pattern S2,..., the Jth light source pattern S J ) are generated based on the set of mask patterns 110. In some embodiments, the multiple light source patterns can be generated by the electronic device 120 based on the received set of mask patterns 110. Alternatively, the multiple light source patterns can also be generated by other electronic devices different from the electronic device 120 (for example, any of the first electronic device 130, the first optimization electronic device 160-1,..., the Mth optimization electronic device 160-M, as shown by the dotted line in Figure 1 ) based on the set of mask patterns 110. The electronic device 120 can receive the multiple light source patterns generated by the other electronic device to perform optimization processing on the received multiple light source patterns, such as performing light source mask optimization.

[0031] The electronic device 120 can use multiple light source patterns (for example, the first light source pattern S1, the second light source pattern S2,..., the Jth light source pattern S J), respectively, as a plurality of initial light source patterns. Each of the plurality of initial light source patterns can form each light source mask pattern combination with the set of mask patterns 110. Correspondingly, J initial light source patterns respectively correspond to J light source mask pattern combinations.

[0032] In some embodiments, the electronic device 120 can iteratively update each light source mask pattern combination to obtain an iteratively updated light source pattern and an iteratively updated set of mask patterns. The electronic device 120 can independently iteratively update each light source mask pattern combination in the plurality of light source mask pattern combinations to obtain an iteratively updated light source pattern and an iteratively updated set of mask patterns.

[0033] In some embodiments, in order to improve the optimization speed, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M (as Figure 1 indicated by the dashed box) can independently optimize one or more light source mask pattern combinations respectively, where M ≤ J. In this case, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M can respectively receive the set of mask patterns 110, and respectively obtain the corresponding one or more light source patterns (for example, can be generated based on the received set of mask patterns 110, or receive the corresponding light source patterns from the electronic device 120 or the first electronic device 130) for subsequent processing. For example, the mth optimization electronic device 160-m (1 ≤ m ≤ M) can perform light source mask optimization on each light source mask pattern combination formed by the obtained light source pattern and the set of mask patterns 110. After iteratively processing the corresponding light source mask pattern combination, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M can input their respective optimization results into the electronic device 120, as Figure 1 indicated by the dashed line.

[0034] The electronic device 120 can determine the optimized light source pattern and the optimized mask pattern based on the plurality of iteratively updated light source mask pattern combinations respectively corresponding to the plurality of light source patterns. In some embodiments, the electronic device can evaluate the plurality of iteratively updated light source mask pattern combinations, and based on the evaluation results, select a target light source mask pattern combination from the plurality of iteratively updated light source mask pattern combinations to determine the optimized light source pattern and the optimized mask pattern. In some embodiments, the electronic device can use the iteratively updated light source pattern in the target light source mask pattern combination as the optimized light source pattern, and use at least one mask pattern in the iteratively updated set of mask patterns in the target light source mask pattern combination as the optimized mask pattern.

[0035] In some embodiments, the electronic device may perform a lithography performance evaluation on the iteratively updated light source mask pattern combinations based on the values of multiple sets of metrics respectively corresponding to the iteratively updated light source mask pattern combinations. In some embodiments, each set of metrics in the multiple sets of metrics includes at least one of the following items: edge placement error, normalized log slope of light intensity, and process window. For example, the electronic device 120 may obtain the values of a set of metrics for each iteratively updated light source mask pattern combination. Based on the values of the set of metrics, the electronic device 120 may select a light source mask pattern combination that meets the requirements (e.g., within the range of the metric values specified by the user). The electronic device 120 may use the iteratively updated light source pattern in the selected light source mask pattern combination as the optimized light source pattern, and use the iteratively updated at least one mask pattern in the selected light source mask pattern combination as the optimized mask pattern.

[0036] In some embodiments, the electronic device may perform evaluations such as cost and / or efficiency on the iteratively updated light source mask pattern combinations, and based on the evaluation results, select a target light source mask pattern combination from the multiple iteratively updated light source mask pattern combinations to determine the optimized light source pattern and the optimized mask pattern. In addition, according to actual needs, the electronic device may also perform evaluations in other aspects on the iteratively updated light source mask pattern combinations, and based on the evaluation results, select a target light source mask pattern combination to determine the optimized light source pattern and the optimized mask pattern.

[0037] Any of the electronic device 120, the first electronic device 130, and the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M may be any device with computing capabilities. As a non-limiting example, the electronic device 120 may be any type of fixed electronic device, mobile electronic device, or portable electronic device, including but not limited to desktop computers, laptop computers, notebook computers, netbook computers, tablet computers, multimedia computers, mobile phones, smart home devices, wearable electronic devices, etc. In some embodiments, all or part of the components of the electronic device 120 may be distributed in the cloud. The present disclosure does not limit the specific type of the electronic device 120.

[0038] In addition, it can also be understood that the electronic device 120, the first electronic device 130, and the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M may constitute a light source mask optimization system 140 according to the embodiments of the present disclosure, which is used to execute the light source mask optimization method according to the embodiments of the present disclosure, and achieve the goal of expanding the lithography process window by optimizing the distribution of light source intensity and mask patterns.

[0039] Figure 2FIG. 200 shows a flowchart of an exemplary method for light source mask optimization according to some embodiments of the present disclosure. For ease of discussion, method 200 will be described in conjunction with Figure 1 to describe method 200. Figure 2 The method 200 in Figure 1 can be executed at the electronic device 120 in

[0040] and any suitable electronic device (e.g., any of the first electronic device 130, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M). In addition, the numbers in the flowchart do not represent the order of execution of these steps. Some or all of these steps can be executed in parallel, or the order of execution can be interchanged, and the present disclosure does not limit this. Figure 1 At block 202, the electronic device 120 can receive a set of mask patterns. In some embodiments, the electronic device 120 can receive a set of mask patterns 110. As

[0041] Figures 3A - 3D shown, the set of mask patterns 110 includes a plurality of mask patterns, e.g., the first mask pattern 110-1, the second mask pattern 110-2, ……, the Nth mask pattern 110-N. In some embodiments, the plurality of mask patterns included in the set of mask patterns 110 received by the electronic device 120 are respectively a plurality of target mask patterns, i.e., the target patterns expected to be imaged on the wafer through the lithography process. Figure 3A FIG. shows a schematic example of 4 target mask patterns. L1 FIG. shows the first target mask pattern 310. The target mask pattern 310 includes main patterns 311~316. The main patterns are line patterns in the vertical direction. The line width of each main pattern is L1 e.g., 65 nm. The first target mask pattern 310 is a periodic pattern, and the period is, for example, 2× L1 . That is, the distance between the edges on the same side of two adjacent main patterns is 2× Figure 3A . As L1 schematically shown, for two adjacent main patterns 311 and 312, the line width of each main pattern is L1 , and the distance between the two left edges of the two main patterns 311 and 312 is 2× L1 . Similarly, the line width of each main pattern in the first target mask pattern 310 is L1 , and the distance between the edges on the same side of two adjacent main patterns is 2×

[0042] Figure 3BThe second target mask pattern 320 is shown. The target mask pattern 320 includes main patterns 321 to 325. The main patterns are line patterns in the vertical direction. The line width of each main pattern is L2 , for example, 75 nm. The line width L2 can be different from Figure 3A the line width in L1 , for example, L2 > L1 . The second target mask pattern 320 can be a periodic pattern, and the period is, for example, 2× L2 . That is, the distance between the edges on the same side of two adjacent main patterns is .

[0043] As Figure 3B shown, for two adjacent main patterns 321 and 322, the line width of each main pattern is L2 , and the distance between the two edges on the left side of these two main patterns 321 and 322 is 2× L2 . Similarly, the line width of each main pattern in the second target mask pattern 320 is L2 , and the distance between the edges on the same side of two adjacent main patterns is 2× L2 .

[0044] Figure 3C The third target mask pattern 330 is shown. The target mask pattern 330 includes main patterns 331 to 333. The main patterns are line patterns in the vertical direction. The line width of each main pattern is L3 , for example, 85 nm. The line width L3 is different from Figure 3A the line width in L1 , and is also different from Figure 3B the line width in L2 . For example, L3 > L2 > L1 . The third target mask pattern 330 can be a periodic pattern, and the period is, for example, 2× L3 . That is, the distance between the edges on the same side of two adjacent main patterns is 2× L3 . As Figure 3C shown, for two adjacent main patterns 331 and 332, the line width of each main pattern is L3 , and the distance between the two edges on the left side of these two main patterns 331 and 332 is 2× L3 . Similarly, the line width of each main pattern in the third target mask pattern 330 is L3 , and the distance between the edges on the same side of two adjacent main patterns is 2× L3 .

[0045] Figure 3D The fourth target mask pattern 340 is shown. The target mask pattern 340 includes main patterns 341 to 343. The main patterns are line patterns in the vertical direction. The line width of each main pattern is L4 , for example, 75 nm. The line width L4 can be the same as Figure 3B the line width in L2 . The line width L4 can also be the same as Figure 3A or Figure 3C the line width in. In addition, the line width L4 can also be other width values, which are not limited in this disclosure. The fourth target mask pattern 340 can be a periodic pattern, and the period is L5 . That is, the distance between the edges on the same side of two adjacent main patterns is L5 . The period L 5 can be a multiple of the line width L 4, which is not limited in this disclosure. As Figure 3D shown, for two adjacent main patterns 341 and 342, the distance between the two edges on the left side of the two main patterns 341 and 342 is L5 . Similarly, the line width of each main pattern in the fourth target mask pattern 340 is L4 , and the distance between the edges on the same side of two adjacent main patterns is L5 .

[0046] The above combines Figures 3A - 3D to show a schematic diagram of a set of mask patterns 110 received by the electronic device 120 at block 202. It can be understood that the set of mask patterns 110 received by the electronic device 120 can include any number of mask patterns and is not limited to 4. In addition, it can also be understood that Figures 3A - 3D the pattern of the target mask pattern shown in is also only schematic. Each target mask pattern can include any number of main patterns, and the shape of the main pattern is not limited to a line pattern in the vertical direction. In addition, the line width of the main pattern in each target mask pattern, whether each target mask pattern is a periodic pattern or the period of each mask pattern can also be set according to the user's needs, which is not limited in this disclosure.

[0047] Return Figure 2 , at block 204, the electronic device 120 can obtain a plurality of light source patterns (for example, the first light source pattern S1, the second light source pattern S2,..., the Jth light source pattern S J), respectively, as a plurality of initial light source patterns. In some embodiments, the plurality of light source patterns are generated based on the set of mask patterns 110. In some embodiments, the plurality of light source patterns generated based on the set of mask patterns 110 are different from each other.

[0048] In some embodiments, the electronic device 120 may generate a plurality of light source patterns (e.g., a first light source pattern S1, a second light source pattern S2,..., a Jth light source pattern S J ) based on a received set of mask patterns 110, and use the generated plurality of light source patterns as a plurality of initial light source patterns for subsequent optimization processing.

[0049] In some other embodiments, the electronic device 120 may receive a plurality of light source patterns as initial light sources. In this case, a plurality of light source patterns (e.g., a first light source pattern S1, a second light source pattern S2,..., a Jth light source pattern S J ) may be generated based on the set of mask patterns 110 by other electronic devices different from the electronic device 120 (e.g., any of the first electronic device 130, the first optimization electronic device 160-1,..., the Mth optimization electronic device 160-M). The other electronic devices that generate the plurality of light source patterns may send the generated plurality of light source patterns to the electronic device 120, so that the electronic device 120 can obtain the plurality of light source patterns and use the obtained plurality of light source patterns as a plurality of initial light sources for subsequent optimization processing.

[0050] The specific implementation of generating light source patterns based on a set of mask patterns including a plurality of target mask patterns will be described in detail below with reference to the accompanying drawings.

[0051] In block 206, for each light source pattern S (e.g., a first light source pattern S1, a second light source pattern S2,..., a Jth light source pattern S J ) in the plurality of light source patterns i (where 1 ≤ i ≤ J; i is a positive integer; J represents the number of light source patterns) and each light source mask pattern combination formed by the set of mask patterns 110 G i , the electronic device 120 may iteratively update each light source pattern S G i in the light source mask pattern combination i and the set of mask patterns 110.

[0052] In some embodiments, the light source mask pattern combination G i includes the light source pattern S i and the set of mask patterns 110. That is, the light source mask pattern combination Gi includes a light source pattern S i , a first mask pattern 110-1, a second mask pattern 110-2... a first N mask pattern 110-N. Specifically, the first light source mask pattern combination G 1 may include a first light source pattern S1, a first mask pattern 110-1, a second mask pattern 110-2... a first N mask pattern 110-N. The second light source mask pattern combination G 2 may include a second light source pattern S2, a first mask pattern 110-1, a second mask pattern 110-2... a first N mask pattern 110-N, and so on. And the Jth light source mask pattern combination G J may include the Jth light source pattern S J , a first mask pattern 110-1, a second mask pattern 110-2... a first N mask pattern 110-N. In some embodiments, the number of light source mask pattern combinations corresponds to the number of light source patterns, and each light source pattern corresponds to a corresponding light source mask pattern combination

[0053] In some embodiments, the electronic device 120 may perform iterative update processing for all the light source mask pattern combinations G 1 ~ G J And the electronic device 120 may perform iterative update operations independently for each light source mask pattern combination G i Alternatively, in order to improve the optimization speed, it may also be performed by

[0054] the first optimization electronic device 160-1 shown in... the Mth optimization electronic device 160-M (as Figure 1 shown by the dashed box in) respectively and independently optimize one or more light source mask pattern combinations Figure 1 i G , where M≤J. In this case, the first optimization electronic device 160-1... the Mth optimization electronic device 160-M may respectively receive the set of mask patterns 110 and respectively obtain one or more light source patterns (for example, may be generated based on the received set of mask patterns 110, or may receive the corresponding light source patterns from the electronic device 120 or the first electronic device 130) for use in subsequent iterative processing. For example, the mth optimization electronic device 160-m (1≤m≤M) may perform light source mask optimization on each light source mask pattern combination formed by each obtained light source pattern and the set of mask patterns 110

[0055] ​For example, the first optimized electronic device 160-1 may receive the second light source pattern S2 and the set of mask patterns 110, and perform iterative update processing on the light source mask pattern combination including the second light source pattern S2, the first mask pattern 110-1, the second mask pattern 110-2, ……, the Nth mask pattern 110-N. G 2 For another example, the Mth optimized electronic device 160-M may receive the (J-1)th light source pattern S （J-1） and the set of mask patterns 110, and perform iterative update processing on the light source mask pattern combination including the (J-1)th light source pattern S （J-1） , the first mask pattern 110-1, the second mask pattern 110-2, ……, the Nth mask pattern 110-N. G (J-1) The Mth optimized electronic device 160-M may also receive the Jth light source pattern S J and the set of mask patterns 110, and perform iterative update processing on the light source mask pattern combination including the Jth light source pattern S J , the first mask pattern 110-1, the second mask pattern 110-2, ……, the Nth mask pattern 110-N. G J Perform iterative update processing.

[0056] In some embodiments, the iterative update operations can be independently performed among each of the electronic devices 120, the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M. That is, for multiple light source mask pattern combinations corresponding to multiple light source patterns respectively, the electronic devices 120, the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M can independently perform iterative update on each light source mask pattern combination among the multiple light source mask pattern combinations.

[0057] The following will describe the specific process of the electronic device (any of the electronic devices 120, the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M) performing iterative update on each light source mask pattern combination G 1 ~ G J in the multiple light source mask pattern combinations G i (where 1≤i≤J; i is a positive integer; J represents the number of light source patterns). G i Perform iterative update.

[0058] Hereinafter, the electronic device 120 will still be taken as an example for illustration. However, it can be understood that any device (any electronic device among the electronic device 120, the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M) that performs iterative update can perform similar operations described below to implement the iterative update operation on the corresponding light source mask pattern combination. Moreover, the iterative update operation described below is applicable to each light source mask pattern combination.

[0059]

[0060] Among them, is the pixel value at the pixel point in the wafer pattern, and, and, is the pixel value at the pixel point in the target mask pattern . P is the number of pixel points in the pattern.

[0061] In addition, it can be understood that the loss function cost may further include other metric indicators concerned by lithography processes, such as, edge placement error (EPE), normalized log slope of light intensity (NILS), process window (PW), etc. Based on different metric indicators, corresponding loss functions can be set for the light source mask pattern combination G i , and the present disclosure does not limit this.

[0062] Since the distributions of the light source pattern and the mask pattern are usually represented by matrices, and each element in the matrix needs to be optimized. Considering that there are many parameters to be optimized, a gradient-based iterative optimization method is usually used.

[0063] Figure 4 FIG. shows a flowchart of a gradient-based iterative optimization method 400 according to an embodiment of the present disclosure. The flowchart of this method 400 can be executed by Figure 1 any electronic device among the electronic device 120, the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M. Hereinafter, the electronic device 120 will be taken as an example for illustration. In addition, the numbers in the flowchart do not represent the execution order of these steps. Some or all of these steps can be executed in parallel, or the execution order can be interchanged, and the present disclosure does not limit this.

[0064] At block 402, the electronic device 120 can determine the light source pattern to be optimized and a set of mask patterns to be optimized. Taking the electronic device 120 performing iterative update on the light source mask pattern combination G i as an example for illustration. The electronic device 120 can determine that the light source pattern to be optimized is the light source pattern S i, and a set of mask patterns to be optimized may include a first mask pattern 110-1, a second mask pattern 110-2,..., an Nth mask pattern 110-N.

[0065] At block 404, the electronic device 120 may construct a loss function cost for the light source pattern to be optimized and the set of mask patterns to be optimized. In some embodiments, the electronic device 120 may construct the loss function cost according to the above formula (1).

[0066] At block 406, the electronic device 120 may determine whether the current iterative update satisfies a termination condition. For example, whether the loss function has met a predetermined requirement (e.g., the loss function converges) or the number of iterative updates has reached a preset threshold number.

[0067] The electronic device 120 may use various appropriate methods to update the light source pattern and the mask pattern, and the present disclosure does not limit this. The present disclosure takes the steepest descent method as an example to illustrate the operation process of the electronic device 120 to update the light source pattern and the mask pattern.

[0068] Assume that the gradient matrix of the loss function cost for the light source pattern is , and the gradient matrix for each mask pattern is . Then the electronic device 120 may update the light source pattern according to the following formula (2) and update each mask pattern according to formula (3):

[0069]

[0070] Wherein, S k+1 and S k represent the light source patterns of the (k + 1)-th iteration and the k-th iteration, M (k+1;j) and M (k;j) represent the j-th mask pattern of the (k + 1)-th iteration and the k-th iteration among the N mask patterns, and 1 ≤ i ≤ N, where N is the number of mask patterns to be updated.

[0071] The electronic device 120 may update the light source pattern and each mask pattern according to the above formulas (2) and (3). For example, in each iteration process, the electronic device 120 may iteratively update the light source pattern based on the first gradient matrix , and iteratively update each mask pattern in the set of mask patterns based on the second gradient matrix . At block 406, the electronic device 120 may determine whether the iterative update operation satisfies a termination condition.

[0072] In response to the iterative update operation not satisfying the termination condition, process 400 proceeds to block 408 to continue updating the light source pattern and the set of mask patterns. In response to the iterative update operation satisfying the termination condition, for example, based on the updated light source pattern S k+1 and mask pattern M (k+1;1) , M (k+1;2) ,..., M (k+1;N) determining that the loss function converges or the number of iteration rounds or the number of iterative updates has reached a preset threshold number of times, process 400 proceeds to block 410, where the electronic device 120 may use the light source pattern that was most recently updated at block 408 S k+1 and mask pattern M (k+1;1) , M (k+1;2) ,... M (k+1;N) determined as the iterative result R .

[0073] In some embodiments, for a light source mask pattern combination G i , after the electronic device 120 performs q rounds of iterative update operations, it may obtain a corresponding iterative result R i , and this iterative result R i includes the light source pattern updated after q rounds of iteration S (i;q) and mask pattern M (i;q;1) , M (i; q;2) ,... M (i; q;N)。

[0074] In some embodiments, the electronic device 120 may perform iterative update processing on the light source mask pattern combinations corresponding to the initial light source S 1 ~ S J respectively, and obtain corresponding iterative results. For example, for the light source mask pattern combination G 1 ~ G J , after the electronic device 120 performs t rounds of iterative update operations, it may obtain a corresponding iterative result R G 1 , and this iterative result R 1 , and this iterative result R 1includes the updated light source pattern after t rounds of iteration S (1;t) and the mask pattern M (1;t;1) 、 M (1;t;2) 、……、 M (1;t;N) 。And so on, for the light source mask pattern combination G J after the electronic device 120 performs b rounds of iterative update operations, the corresponding iterative result R can be obtained J This iterative result R i includes the updated light source pattern after b rounds of iteration S (J;b) and the mask pattern M (J; b;1) 、 M (J; b;2) 、……、 M (J; b;N)。

[0075] In addition, when an optimized electronic device different from the electronic device 120 (for example, an optimized electronic device among the first optimized electronic device 160-1, ……, the Mth optimized electronic device 160-M) performs iterative update processing on the light source mask pattern combination, the corresponding optimized electronic device can perform similar operations as described above and obtain an iterative result R corresponding to the light source mask pattern combination, as described above.

[0076] Return to Figure 2 At block 208, the electronic device 120 can determine an optimized light source pattern and an optimized mask pattern based on multiple iteratively updated light source mask pattern combinations respectively corresponding to multiple light source patterns.

[0077] In some embodiments, the electronic device can evaluate multiple iteratively updated light source mask pattern combinations, and based on the evaluation results, select a target light source mask pattern combination from the multiple iteratively updated light source mask pattern combinations to determine an optimized light source pattern and an optimized mask pattern. The electronic device 120 can use the iteratively updated light source pattern in the target light source mask pattern combination as the optimized light source pattern, and use at least one mask pattern in the iteratively updated set of mask patterns in the target light source mask pattern combination as the optimized mask pattern.

[0078] In some embodiments, an electronic device may perform a lithography performance evaluation on an iteratively updated combination of light source mask patterns based on values of multiple sets of metrics respectively corresponding to the iteratively updated combinations of light source mask patterns. In some embodiments, the electronic device may perform an evaluation such as cost and / or efficiency evaluation on the iteratively updated combination of light source mask patterns, and based on the evaluation results, select a target combination of light source mask patterns from the multiple iteratively updated combinations of light source mask patterns to determine an optimized light source pattern and an optimized mask pattern. In addition, according to actual requirements, the electronic device may also perform evaluations in other aspects on the iteratively updated combination of light source mask patterns, and based on the evaluation results, select a target combination of light source mask patterns to determine an optimized light source pattern and an optimized mask pattern.

[0079] The following will take the example of an electronic device determining an optimized light source pattern and an optimized mask pattern based on a lithography performance evaluation of multiple iteratively updated combinations of light source mask patterns for illustration. The electronic device 120 may determine values of multiple sets of metrics respectively corresponding to the multiple iteratively updated combinations of light source mask patterns based on the iteration results R respectively corresponding to the multiple iteratively updated combinations of light source mask patterns. The electronic device 120 may select a target combination of light source mask patterns from the multiple iteratively updated combinations of light source mask patterns based on the values of the multiple sets of metrics respectively corresponding to the multiple iteratively updated combinations of light source mask patterns. In some embodiments, the metrics may include at least one of the following: edge placement error, normalized log slope of light intensity, and process window.

[0080] In some embodiments, the electronic device 120 may determine the set of combinations of light source mask patterns according to the iteration result R obtained at block 206. G i The values of the metrics after the above iterative update operation MTR i . For example, the electronic device 120 may determine the edge placement error associated with each mask pattern in the iteration result R i , the normalized log slope of light intensity associated with the iteratively updated light source pattern, and the process window associated with the iteration result.

[0081] For multiple sets of combinations of light source mask patterns, the electronic device 120 may obtain the values of the metrics respectively corresponding to the multiple sets of combinations of light source mask patterns. For example, the electronic device 120 may generate corresponding values of the metrics based on the iteration results. Alternatively, the electronic device 120 may receive the corresponding values of the metrics from the electronic device that generates the iteration results, and the present disclosure does not limit this.

[0082] The electronic device 120 may select a target light source mask pattern combination from multiple iteratively updated light source mask pattern combinations according to the values of multiple sets of metric indicators obtained. For example, the electronic device 120 may select, as the target light source mask pattern combination, the light source mask pattern combination corresponding to the values of the metric indicators that meet the requirements according to the reference value or the range of the reference value set by the user.

[0083] In some embodiments, the smaller the value of EPE, the better. Preferably, EPE is less than 1.0 nm. The larger the value of NILS, the better. Preferably, NILS is greater than 1.0 nm. The larger the depth of focus (DOF) of the process window, the better. The requirements vary for different process nodes. Preferably, at 5% exposure latitude (EL), DOF is greater than 80 nm or 100 nm.

[0084] The electronic device 120 may use the iteratively updated light source pattern in the determined target light source mask pattern combination as the optimized light source pattern. The electronic device 120 may use at least one mask pattern in the iteratively updated mask patterns in the determined target light source mask pattern combination as the optimized mask pattern. In some embodiments, for the N mask patterns in the iterative update, the electronic device 120 may select at least one mask pattern that meets the requirements as the optimized mask pattern according to the values of a set of metric indicators (such as EPE, NILS, DOF, etc.). The present disclosure does not limit the number of selected mask patterns, and the user may select an appropriate number of iterated mask patterns according to the needs.

[0085] The implementation manner of the electronic device for evaluating other aspects of multiple iteratively updated light source mask pattern combinations may be similar to the principle of the implementation manner for lithography performance evaluation above or may be implemented in any appropriate manner. The present disclosure does not limit this.

[0086] According to the solution for light source mask optimization proposed in the embodiments of the present disclosure, by using multiple initial light sources for optimization, the light source pattern and the mask pattern that meet the requirements can be selected from multiple sets of optimization results as the target optimization results. Thus, the probability of the optimization falling into a local optimal solution can be reduced, and the probability of obtaining a more compliant optimization result can be increased. At the same time, according to the solution for light source mask optimization in the embodiments of the present disclosure, by generating multiple initial light source patterns based on the optical diffraction characteristics of the target mask pattern, the generated initial light source patterns can be related to the imaging optical behavior of the target mask pattern, so that the generated initial light sources can have good imaging performance. Furthermore, a significantly increased process window can be provided.

[0087] In some embodiments, the method for optimizing a light source mask according to an embodiment of the present disclosure may further include: generating, by the electronic device 120 or another electronic device different from the electronic device 120 (e.g., an electronic device in the optimization electronic devices such as the first electronic device 130, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M), a plurality of light source patterns (e.g., the first light source pattern S1, the second light source pattern S2, ……, the Jth light source pattern S J ), as a plurality of initial light source patterns respectively. In some embodiments, the plurality of light source patterns are different from each other. The specific implementation process of the electronic device (the electronic device 120 or another electronic device) generating a plurality of light source patterns based on the received set of mask patterns 110 will be described in detail below.

[0088] For the sake of simplicity, the electronic device 120 will be taken as an example for illustration below. Those skilled in the art can understand that other electronic devices different from the electronic device 120 (e.g., an electronic device in the optimization electronic devices such as the first electronic device 130, the first optimization electronic device 160-1, ……, the Mth optimization electronic device 160-M) can also perform similar operations to generate a plurality of light source patterns. Figure 5 FIG. 500 is a flowchart showing a method for generating a plurality of light source patterns based on a set of mask patterns according to an embodiment of the present disclosure.

[0089] In block 502, the electronic device 120 may obtain the pattern information of each target mask pattern in the set of mask patterns. In some embodiments, the set of mask patterns is the set of mask patterns 110 received by the electronic device 120 in method 200 and used for iterative processing, and the set of mask patterns includes the first mask pattern 110-1, the second mask pattern 110-2, ……, the Nth mask pattern 110-N. In some embodiments, the plurality of mask patterns included in the set of mask patterns 110 are respectively a plurality of target mask patterns, that is, the target patterns expected to be imaged on the wafer through the lithography process. Figures 3A - 3D FIG. schematically shows an example of a plurality of target mask patterns in the set of mask patterns 110. Each schematic target mask pattern has been described in detail above, and for the sake of simplicity, it will not be repeated here.

[0090] In some embodiments, for each target mask pattern 110-n (1 ≤ n ≤ N), the electronic device 120 may generate a mask matrix for the target mask pattern 110-n. For example, the electronic device 120 may rasterize the target mask pattern, that is, the electronic device 120 may convert the target mask pattern 110-n from a polygon format to a pixel format. In some embodiments, the electronic device 120 may set the pixels within the polygon of the target mask pattern 110-n to 1 and set the pixels outside the polygon of the target mask pattern 110-n to 0, thereby generating a mask matrix M for the target mask pattern 110-n maskn .

[0091] In some embodiments, the electronic device 120 may perform a Fourier transform on the mask matrix M maskn to obtain a complex matrix Mc corresponding to the mask matrix M maskn . And the complex matrix Mc n indicates the spectral information of the corresponding target mask pattern 110-n n .

[0092] In some embodiments, performing a Fourier transform on the mask matrix M maskn can obtain the diffraction spectrum of the target mask pattern. Correspondingly, the complex matrix Mc corresponding to the target mask pattern 110-i n indicates the spectral information of the corresponding target mask pattern 110-n

[0093] In some embodiments, the electronic device 120 may convert the complex matrix M corresponding to each target mask pattern 110-n obtained in block 502 cn into a real matrix M rn . In some embodiments, the electronic device may take the modulus of each element in the complex matrix M cn and use each matrix obtained after taking the modulus as the real matrix M cn corresponding to the complex matrix M rn . In some embodiments, the real matrix M rn indicates the pattern information of the target mask pattern 110-n

[0094] In block 504, the electronic device 120 may determine a light source pattern corresponding to the target mask pattern 110-n based on the pattern information of the target mask pattern 110-n obtained in block 502

[0095] The following will be combined with Figure 6 describe the specific implementation manners for determining the light source pattern corresponding to each target mask pattern Figure 6The flowchart of method 600 for determining a light source pattern corresponding to a target mask pattern based on the pattern information according to an embodiment of the present disclosure is shown. Hereinafter, taking the electronic device 120 as an example, it will be described in conjunction with Figure 6 This will be described. Those skilled in the art can understand that Figure 1 other electronic devices in the light source mask optimization system 104 in Figure 6 can also perform similar operations to generate multiple light source patterns. In addition, Figure 6 method 600 in

[0096] is used to determine or generate a light source pattern corresponding to a target mask pattern among a group of mask patterns. For each other target mask pattern, method 600 in rn signal can be used to generate a light source pattern corresponding to it.

[0097] The electronic device 120 can also determine the number of elements pixel num of multiple elements (for example, all elements) in the real number matrix. Further, the electronic device 120 can sum the values of multiple elements (for example, all elements) in the real number matrix and obtain the sum value signal sum . The electronic device 120 can determine the pupil filling rate PFR of the real number matrix based on the calculated sum signal sum , the maximum value max signal of the elements, and the number of elements pixel num . In some embodiments, the electronic device 120 can determine the pupil filling rate PFR according to formula (7):

[0098]

[0099] Return Figure 6 , in block 604, the electronic device 120 determines a comparison between the pupil filling rate PFR determined in block 602 and a pupil filling rate threshold. In some embodiments, the pupil filling rate threshold indicates the minimum PRF and can be preset.

[0100] In response to the pupil filling ratio PFR being greater than the pupil filling ratio threshold, the process of method 600 proceeds to block 622. At block 622, the electronic device 120 normalizes the real number matrix. At block 624, the electronic device 120 determines a light source pattern corresponding to the target mask pattern 110-n based on the normalized real number matrix. For example, the value of each element in the normalized real number matrix can correspond to the intensity of each pixel in the light source pattern to be generated. The electronic device 120 can generate the light source pattern based on this correspondence.

[0101] In some embodiments, in response to the pupil filling ratio PFR not being greater than the pupil filling ratio threshold, the process of method 600 proceeds to block 612. At block 612, the electronic device 120 can blur the real number matrix. Each time the blurring process is performed, the electronic device 120 compares the pupil filling ratio of the blurred real number matrix with the pupil filling ratio threshold at block 604. The electronic device 120 can calculate the pupil filling ratio for the blurred real number matrix in the manner described above. In response to the pupil filling ratio not being greater than the pupil filling ratio threshold, the electronic device 120 continues to blur the real number matrix at block 612 until the pupil filling ratio of the real number matrix is greater than the pupil filling ratio threshold.

[0102] The implementation process of blurring the real number matrix will be described below with reference to the accompanying drawings. Figure 7 FIG. shows a schematic implementation process of blurring a real number matrix according to an embodiment of the present disclosure. Figure 7 The real number matrix M1 in represents the matrix after blurring the real number matrix M. Figure 7 The values of the matrix elements in are only illustrative. And, Figure 7 Taking a 5×5 matrix as an example for illustration, it can be understood that, Figure 7 the implementation process of the blurring operation in can be applied to matrices of any size.

[0103] During the process of blurring the real number matrix M, the electronic device 120 can determine the elements to be allocated in the real number matrix. In some embodiments, the elements to be allocated can be the elements with relatively large element values in the matrix. For example, the electronic device 120 can select the element with the largest value in the current matrix as the element to be allocated in each blurring process. Taking the matrix M in as an example, the maximum value of the elements in the current matrix is the element a in the first column of the third row Figure 7 and the element a in the fourth column of the second row 31 . In one blurring process, the electronic device 120 can select any element of element a 24 and a 31 as the element to be allocated. 24 In.

[0104] The electronic device 120 may determine a first direction between the element to be allocated and the central element in the real number matrix. Figure 7 In the example, when the element to be assigned is element a 31 When the electronic device can determine the element a 31 With the central element a 33 The first direction between Figure 7 middle element a 31 With the central element a 33 When the selected element to be assigned is element a 24 When the electronic device can determine the element a 24 With the central element a 33 The first direction between Figure 7 middle element a 24 With the central element a 33 As indicated by the arrow lines between them.

[0105] The electronic device 120 may distribute the value of the element to be distributed at least partially to multiple elements in the second direction along a second direction perpendicular to the first direction. 31 When the electronic device 120 can move along the axis corresponding to the element a 31 and the central element a 33 The first direction is perpendicular to the second direction, and the element a 31 The value of is at least partially distributed to multiple elements in the second direction. Figure 7 As shown, the electronic device 120 can 31 The value of is at least partially assigned to element a 21 and element a 42 ,For example, Figure 7 As shown in 21 and element a 42 are both 0.2. When the element to be assigned is element a 24 When the electronic device 120 can move along the axis corresponding to the element a 24 and the central element a 33 The first direction is perpendicular to the second direction, and the element a 24 The value of is at least partially distributed to multiple elements in the second direction. For example, the electronic device 120 may distribute the value of element a to the plurality of elements in the second direction. 24 The value of is at least partially assigned to element a 13 and element a 35 , so that element a 13 and element a 35 For example, Figure 7 0.2 shown in .

[0106] It is understandable that the above examples are merely illustrative. The electronic device 120 can select multiple elements in the second direction to assign values to the elements to be assigned, and the values assigned to each element are not necessarily equal.

[0107] Figure 8 FIG. shows a schematic comparison diagram of an image obtained based on a real number matrix before blurring and an image obtained based on a real number matrix after blurring according to an embodiment of the present disclosure. It can be seen that by performing blurring on the real number matrix, the image generated based on the matrix after blurring can be made uniform and smooth.

[0108] As described above, the electronic device 120 can generate a light source pattern based on the correspondence between the value of each element in the normalized real number matrix and the intensity of each pixel of the light source pattern to be determined.

[0109] Figures 9A - 9C FIG. shows schematic diagrams of three light source patterns generated according to an embodiment of the present disclosure. It is understandable that this is merely illustrative, and those skilled in the art can obtain light source patterns of any shape related to the target mask pattern according to the principles disclosed in the embodiments of the present disclosure.

[0110] Figure 9D FIG. shows a schematic diagram of a light source pattern for dipole illumination. For a one-dimensional line in the vertical direction (such as Figures 3A - 3D the main pattern in), usually the horizontal dipole illumination shown in Figure 9D is selected. In the case of selecting the light source pattern of the dipole illumination shown in Figure 9D for light source mask optimization, the range of the depth of focus (DOF) of the optimal lithography process window obtained is usually less than 270 nm. And by using the initial light source pattern generated according to the embodiments of the present disclosure (such as Figures 9A - 9C shown), the depth of focus (DOF) of the optimal lithography process window obtained is close to 300 nm. Thus, it can be seen that by using the light source mask optimization scheme according to the embodiments of the present disclosure, the lithography process window is significantly expanded.

[0111] Figure 10 FIG. shows a schematic block diagram of an example device 1000 that can be used to implement the embodiments of the present disclosure. The device 1000 can be used to implement Figure 1 any of the electronic devices such as the electronic device 120, the first electronic device 130, the first optimization electronic device 160-1,..., the Mth optimization electronic device 160-M. As Figure 10As shown, device 1000 includes a processing unit (e.g., a central processing unit CPU) 1001, which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) 1002 or computer program instructions loaded from a storage unit 1008 into a random access memory (RAM) 1003. In the RAM 1003, various programs and data required for the operation of the device 1000 can also be stored. The processing unit 1001, the ROM 1002, and the RAM 1003 are connected to each other via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0112] Multiple components in the device 1000 are connected to the I / O interface 1005, including: an input unit 1006, such as a keyboard, a mouse, etc.; an output unit 1007, such as various types of displays, speakers, etc.; a storage unit 1008, such as a magnetic disk, an optical disc, etc.; and a communication unit 1009, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 1009 allows the device 1000 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0113] The processing unit 1001 executes the various methods and processes described above, such as method 200, method 400, method 500, and method 600. For example, in some embodiments, method 200, method 400, method 500, and method 600 are implemented as computer software programs that are tangibly contained in a machine-readable medium, such as the storage unit 1008. In some embodiments, part or all of the computer program can be loaded and / or installed onto the device 1000 via the ROM 1002 and / or the communication unit 1009. When the computer program is loaded into the RAM 1003 and executed by the processing unit 1001, one or more steps of the methods 200, 400, 500, and 600 described above can be executed. Alternatively, in other embodiments, the processing unit 1001 can be configured to execute methods 200, 400, 500, and 600 in any other appropriate manner (e.g., by means of firmware).

[0114] The functions described above herein can be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that can be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SOCs), complex programmable logic devices (CPLDs), and so on.

[0115] The program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the machine, partially on the machine, executed partially on the machine as an independent software package and partially on a remote machine, or executed entirely on a remote machine or server.

[0116] In the context of the present disclosure, a machine-readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0117] In addition, although the operations are depicted in a particular order, this should be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although a number of specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present disclosure. Certain features described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations.

[0118] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are merely example forms of implementing the claims.

Claims

1. A method for light source mask optimization, comprising: Receiving a set of mask patterns; Obtaining a plurality of light source patterns to be used as a plurality of initial light source patterns respectively, wherein the set of mask patterns includes a plurality of target mask patterns, and wherein each light source pattern among the plurality of light source patterns is generated based on the spectral information of each target mask pattern among the plurality of target mask patterns, and the spectral information is indicated by a complex matrix corresponding to the target mask pattern; For each combination of a light source mask pattern formed by each light source pattern among the plurality of light source patterns and the set of mask patterns, iteratively updating each light source pattern and the set of mask patterns in each combination of the light source mask pattern to obtain an iteratively updated combination of the light source mask pattern; And Based on a plurality of iteratively updated combinations of the light source mask pattern respectively corresponding to the plurality of light source patterns, determining an optimized light source pattern and an optimized mask pattern.

2. The method according to claim 1, wherein obtaining a plurality of light source patterns includes: Generating each light source pattern based on the spectral information of each target mask pattern among the set of target mask patterns.

3. The method according to claim 2, wherein generating the plurality of light source patterns includes: For each target mask pattern among the plurality of target mask patterns: Obtaining the pattern information of each target mask pattern; And Based on the pattern information, determining a light source pattern corresponding to each target mask pattern.

4. The method according to claim 3, wherein, Obtaining the pattern information of each target mask pattern includes: Generating a mask matrix corresponding to each target mask pattern; and Performing a Fourier transform on the mask matrix to obtain the complex matrix corresponding to the mask matrix, wherein the complex matrix indicates the spectral information of each target mask pattern; and Converting the complex matrix corresponding to each target mask pattern into a real matrix, wherein the real matrix indicates the pattern information of each target mask pattern.

5. The method according to claim 4, wherein based on the pattern information, determining a light source pattern corresponding to each target mask pattern includes: Determining the pupil fill rate of the real matrix; In response to the pupil fill rate being greater than a pupil fill rate threshold, performing a normalization process on the real matrix; And Based on the normalized real matrix, determining the light source pattern corresponding to each target mask pattern.

6. The method according to claim 4, wherein based on the pattern information, determining a light source pattern corresponding to each target mask pattern includes: Determining the pupil fill rate of the real matrix; In response to the pupil fill rate not being greater than the pupil fill rate threshold, iteratively performing a blurring process on the real matrix until the pupil fill rate of the real matrix is greater than the pupil fill rate threshold; And Based on the real matrix after the iterative blurring process, determining the light source pattern corresponding to each target mask pattern.

7. The method according to claim 6, wherein iteratively performing a blurring process on the real matrix includes: In each iteration: Determine the elements to be allocated in the real number matrix; Determine the first direction between the element to be allocated and the central element of the real number matrix; And Along a second direction perpendicular to the first direction, at least partially allocate the value of the element to be allocated to a plurality of elements in the second direction.

8. The method according to any one of claims 5 to 7, wherein determining the pupil filling rate of the real number matrix includes: Determine the maximum value of the elements among the plurality of elements in the real number matrix; Determine the number of elements in the plurality of elements in the real number matrix; Determine the sum of the element values of the plurality of elements; And Based on the sum of the element values, the maximum value of the elements, and the number of elements, determine the pupil filling rate of the real number matrix.

9. The method according to claim 1, wherein determining the optimized light source pattern and the optimized mask pattern includes: Evaluate the plurality of iteratively updated light source mask pattern combinations; And Based on the evaluation results, select a target light source mask pattern combination from the plurality of iteratively updated light source mask pattern combinations to determine the optimized light source pattern and the optimized mask pattern.

10. The method according to claim 9, wherein determining the optimized light source pattern and the optimized mask pattern includes: Use the iteratively updated light source pattern in the target light source mask pattern combination as the optimized light source pattern; And Use at least one mask pattern in the iteratively updated set of mask patterns in the target light source mask pattern combination as the optimized mask pattern.

11. The method according to claim 9, wherein evaluating the plurality of iteratively updated light source mask pattern combinations includes: Based on the values of multiple sets of metric indicators respectively corresponding to the plurality of iteratively updated light source mask pattern combinations, perform lithography performance evaluation on the iteratively updated light source mask pattern combinations.

12. The method according to claim 11, wherein each set of metric indicators in the multiple sets of metric indicators includes at least one of the following items: edge placement error, normalized log slope of light intensity, and process window.

13. The method according to claim 1, wherein iteratively updating each light source pattern and the set of mask patterns in each light source mask pattern combination includes: Determine the first gradient matrix of the loss function of the light source mask pattern combination with respect to the light source pattern; Determine the second gradient matrix of the loss function with respect to the set of mask patterns; And In each iteration process: Based on the first gradient matrix, update the light source pattern; And Based on the second gradient matrix, update each mask pattern in the set of mask patterns.

14. The method according to claim 1, wherein each light source mask pattern combination is independently iteratively updated.

15. An electronic device, the device includes: One or more processors; And A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, causing the electronic device to execute the method according to any one of claims 1-14.

16. A computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method described in any one of claims 1-14 is implemented.

17. A computer program product comprising program code, and when the program code is executed by a processor, the method described in any one of claims 1-14 is implemented.

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