Method, apparatus, storage medium and program product for light source mask optimization

Abstract

The embodiment of the invention provides a method and equipment for optimizing a light source mask, a storage medium and a program product. The method includes receiving a set of mask patterns. The method further includes acquiring a plurality of light source patterns, respectively, as a plurality of initial light source patterns, where the plurality of light source patterns are generated based on the set of mask patterns. The method further includes iteratively updating each light source pattern in the light source mask pattern combination and the set of mask patterns for each light source mask pattern combination formed by each light source pattern in the plurality of light source patterns and the set of mask patterns 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 relate generally 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] Photolithography is a key process in the manufacturing of integrated circuits. The photolithography process uses the principle of photochemical reaction and chemical and physical etching methods to transfer the pattern prepared on the mask to the wafer. The photolithography process can be described by optical and chemical models with the help of mathematical formulas. When light is irradiated on the mask, it diffracts. The diffraction is collected by the projection lens and converged 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, the photoresist becomes partially soluble in the developer. This is a chemical process.

[0003] As semiconductor manufacturing process nodes continue to move downward, the minimum line width of integrated circuits has become much smaller than the wavelength of the light source in the photolithography process. The diffraction effect of light restricts the resolution of photolithography imaging, which in turn leads to a narrowing of the process window and a decrease in yield. Therefore, the photolithography process requires the use of resolution enhancement technology.

[0004] As an important lithography resolution enhancement technology, source mask coordinated optimization (SMO; or "source mask optimization") can simultaneously consider the light source illumination mode and mask pattern, and achieve the goal of expanding the lithography process window by optimizing the light source intensity and the distribution of the mask pattern. Therefore, source mask optimization technology is a key technology to improve lithography resolution and process window. Summary of the invention

[0005] According to an example embodiment of the present disclosure, a scheme 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 acquiring a plurality of light source patterns to serve as a plurality of initial light source patterns, respectively, wherein the plurality of light source patterns are generated based on the set of mask patterns. The method also includes iteratively updating each light source pattern and the set of mask patterns in the light source mask pattern combination for each light source pattern in the plurality of light source patterns and each light source mask pattern combination formed by the set of mask patterns, so as 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 corresponding to the plurality of light source patterns, respectively.

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

[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 a program code, and 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 contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended 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] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0012] Figure 1 shows an example environment in which embodiments of the present disclosure can be implemented;

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

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

[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 for 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 for determining a light source pattern corresponding to a target mask pattern based on pattern information of the target mask pattern according to an embodiment of the present disclosure;

[0018] Figure 7 The following is a schematic implementation process of performing fuzzy processing on a real number matrix according to an embodiment of the present disclosure;

[0019] Figure 8 A schematic comparison diagram showing 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] Figure 9A-9C A schematic example diagram showing three light source patterns determined according to an embodiment of the present disclosure;

[0021] Fig.9D A schematic illustration of a light source pattern showing dipole illumination; and

[0022] Fig.10 A block diagram of an electronic device capable of implementing an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0024] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part 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. Other explicit and implicit definitions may also be included below.

[0025] As briefly mentioned above, light source mask co-optimization or light source mask optimization is an important lithography resolution enhancement technology, which achieves the goal of expanding the lithography process window by optimizing the light source intensity and the distribution of the mask pattern. Generally, light source mask optimization requires evaluating the lithography imaging performance of different combinations of light source patterns and mask patterns, and updating the light source pattern and mask pattern according to the evaluation results. In order to take into account various mask patterns with different distributions, an annular light source or a dipole light source is usually selected as the initial light source pattern to perform light source mask optimization. That is, with an annular light source pattern or a dipole light source as the initial light source, the light source pattern and the mask pattern are iteratively updated.

[0026] In existing light source mask optimization schemes, a single initial light source is usually used to perform light source mask optimization to iteratively update the light source pattern and mask pattern. However, the single initial light source limits the convergence path of light source mask optimization, which is not conducive to the light source mask optimization to jump out of the local optimal solution. In addition, the optimization result of light source mask optimization is also highly correlated with the initial light source. In light source mask optimization technology, a parameterized single initial light source is usually determined based on experience. For example, a ring light source or a dipole light source (such as Fig.9D The parameterized light source such as the diode illumination light source shown in the figure is used as the initial light source. However, the parameterized light source determined based on experience has a large randomness, it is difficult to take into account multiple target mask patterns at the same time, and it is irrelevant to the imaging optical behavior of the target mask pattern, and it is difficult to guarantee that it is a good initial light source.

[0027] In order to at least solve the above technical problems, according to an embodiment of the present disclosure, a method for light source mask optimization is proposed. The method includes receiving a group of mask patterns. The method also includes obtaining a plurality of light source patterns to serve as a plurality of initial light source patterns, respectively, wherein the plurality of light source patterns are generated based on the group of mask patterns. The method also includes iteratively updating each light source pattern and the group of mask patterns in the light source mask pattern combination for each light source pattern in the plurality of light source patterns and each light source mask pattern combination formed by the group of mask patterns, so as 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 corresponding to the plurality of light source patterns, respectively.

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

[0029] Figure 1 1 shows an example environment 100 in which various embodiments of the present disclosure can be implemented. Figure 1 As shown, the electronic device 120 may receive a set of mask patterns 110, wherein the set of mask patterns 110 includes a plurality of mask patterns, for example, a first mask pattern 110-1, a second mask pattern 110-2, ..., an Nth mask pattern 110-N. The plurality of mask patterns included in the set of mask patterns 110 input into the electronic device 120 may be a plurality of target mask patterns, i.e., target patterns that are expected to be imaged on a wafer through a photolithography process.

[0030] The electronic device 120 may also obtain a plurality of light source patterns (eg, a first light source pattern S1, a second light source pattern S2, ..., a Jth light source pattern S J ) are used as a plurality of initial light source patterns. The 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 ) is generated based on the set of mask patterns 110. In some embodiments, the plurality of light source patterns may be generated by the electronic device 120 based on the received set of mask patterns 110. Alternatively, the plurality of light source patterns may also be generated by other electronic devices different from the electronic device 120 (e.g., any electronic device of the first electronic device 130, the first optimization electronic device 160-1, ..., the Mth optimization electronic device 160-M, such as Figure 1 The plurality of light source patterns (shown by the dashed line in the figure) are generated based on the group of mask patterns 110. The electronic device 120 may receive a plurality of light source patterns generated by the other electronic device to optimize the received plurality of light source patterns, for example, perform light source mask optimization.

[0031] The electronic device 120 may form a plurality of light source patterns (eg, a first light source pattern S1, a second light source pattern S2, ..., a Jth light source pattern S J) are respectively used as a plurality of initial light source patterns. Each of the plurality of initial light source patterns can constitute each light source mask pattern combination with the group of mask patterns 110. Accordingly, the J initial light source patterns correspond to the J light source mask pattern combinations respectively.

[0032] In some embodiments, the electronic device 120 may 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 may independently iteratively update each light source mask pattern combination in a 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 (such as Figure 1 In this case, the first optimizing electronic device 160-1, ..., the Mth optimizing electronic device 160-M may respectively receive the group of mask graphics 110, and respectively obtain one or more corresponding light source graphics (for example, may be generated based on the received group of mask graphics 110, or may receive the corresponding light source graphics from the electronic device 120 or the first electronic device 130) for subsequent processing. For example, the mth optimizing electronic device 160-m (1≤m≤M) may perform light source mask optimization on each light source mask graphic combination consisting of each acquired light source graphic and the group of mask graphics 110. After iterative processing of the corresponding light source mask graphic combinations, the first optimizing electronic device 160-1, ..., the Mth optimizing electronic device 160-M may input their respective optimization results into the electronic device 120, as shown in FIG. Figure 1 Indicated by the dotted line.

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

[0035] In some embodiments, the electronic device may perform lithography performance evaluation on the iteratively updated light source mask pattern combination based on the values ​​of multiple groups of metric indicators corresponding to multiple iteratively updated light source mask pattern combinations. In some embodiments, each group of metric indicators in the multiple groups of metric indicators includes at least one of the following items: edge placement error, normalized light intensity logarithmic slope, and process window. For example, the electronic device 120 may obtain the value of a group of metric indicators for each iteratively updated light source mask pattern combination. Based on the value of the group of metric indicators, the electronic device 120 may select a light source mask pattern combination that meets the requirements (for example, meets the range of indicator 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 an optimized light source pattern, and use the iteratively updated at least one mask pattern in the selected light source mask pattern combination as an optimized mask pattern.

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

[0037] Any electronic device among the electronic device 120, the first electronic device 130, and the first optimized electronic device 160-1, ..., the Mth optimized electronic device 160-M can be any device with computing capabilities. As a non-limiting example, the electronic device 120 can be any type of fixed electronic device, mobile electronic device, or portable electronic device, including but not limited to a desktop computer, a laptop computer, a notebook computer, a netbook computer, a tablet computer, a multimedia computer, a mobile phone, a smart home device, a wearable electronic device, etc. In some embodiments, all or part of the components of the electronic device 120 can 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 optimization electronic device 160-1, ..., the Mth optimization electronic device 160-M can constitute a light source mask optimization system 140 according to an embodiment of the present disclosure, which is used to execute the light source mask optimization method according to an embodiment of the present disclosure, and achieve the goal of expanding the lithography process window by optimizing the light source intensity and the distribution of the mask pattern.

[0039] Figure 2FIG. 2 is a flowchart of an exemplary method 200 for light source mask optimization according to some embodiments of the present disclosure. Figure 1 Method 200 is described. Figure 2 The method 200 in can be Figure 1 The electronic device 120 and any suitable electronic device (for example, the first electronic device 130, the first optimized electronic device 160-1, ..., any electronic device in the Mth optimized electronic device 160-M) are executed. In addition, the numbers in the flowchart do not indicate the order in which these steps are executed. Some or all of these steps can be executed in parallel, or the execution order can be interchanged, which is not limited in the present disclosure.

[0040] At block 202, the electronic device 120 may receive a set of mask patterns. In some embodiments, the electronic device 120 may receive a set of mask patterns 110. Figure 1 As shown, the group of mask patterns 110 includes a plurality of mask patterns, for example, a first mask pattern 110-1, a second mask pattern 110-2, ..., an Nth mask pattern 110-N. In some embodiments, the plurality of mask patterns included in the group of mask patterns 110 received by the electronic device 120 are a plurality of target mask patterns, that is, target patterns that are expected to be imaged on a wafer through a photolithography process.

[0041] Figures 3A-3D Schematic examples of four target mask patterns are shown respectively. Figure 3A The first target mask pattern 310 is shown in FIG. The target mask pattern 310 includes main patterns 311 to 316. The main patterns are line patterns in the vertical direction. The line width of each main pattern is L1 , for example, 65nm. 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 of two adjacent main figures on the same side is 2× L1 .like Figure 3A As shown, for two adjacent main graphics 311 and 312, the line width of each main graphic is L1 , and the distance between the two edges on the left side of the two main graphics 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 of two adjacent main figures on the same side is 2× L1 .

[0042] Figure 3BThe second target mask pattern 320 is shown in FIG. 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, 75nm. Line width L2 Can be different from Figure 3A Line width in L1 ,For example, L2 > L1 The second target mask pattern 320 may be a periodic pattern, and the period is, for example, 2× L2 That is, the distance between the edges of two adjacent main figures on the same side is .

[0043] like Figure 3B As shown, for two adjacent main graphics 321 and 322, the line width of each main graphic is L2 , and the distance between the two edges on the left side of the two main graphics 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 of two adjacent main figures on the same side is 2× L2 .

[0044] Figure 3C The third target mask pattern 330 is shown in FIG. 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, 85nm. Line width L3 Different from Figure 3A Line width in L1 , and is also different from Figure 3B Line width in L2 .For example, L3>L2 > L1 The third target mask pattern 330 may be a periodic pattern, and the period is, for example, 2× L3 That is, the distance between the edges of two adjacent main figures on the same side is 2× L3 .like Figure 3C As shown, for two adjacent main graphics 331 and 332, the line width of each main graphic is L3 , and the distance between the two edges on the left side of the two main graphics 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 of two adjacent main figures on the same side is 2× L3 .

[0045] Figure 3D The fourth target mask pattern 340 is shown in FIG. 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, 75nm. Line width L4 Can be used with Figure 3B Line width in L2 Same. Line Width L4 You can also Figure 3A or Figure 3C In addition, the line width L4 The fourth target mask pattern 340 may be a periodic pattern, and the period is L5 That is, the distance between the edges of two adjacent main figures on the same side is L5 .cycle L 5 can be the line width L 4, which is not limited in the present disclosure. Figure 3D As shown in FIG. 1 , for two adjacent main graphics 341 and 342, the distance between the two edges on the left sides of the two main graphics 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 of two adjacent main figures on the same side is L5 .

[0046] Combination of the above Figures 3A-3D 2 is a schematic diagram showing a set of mask patterns 110 received by the electronic device 120 at block 202. It is understood that the set of mask patterns 110 received by the electronic device 120 may include any number of mask patterns and is not limited to 4. In addition, it is also understood that Figures 3A-3D The target mask pattern shown in the figure is also only for illustration. Each target mask pattern may 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 and whether each target mask pattern is a periodic pattern or the period of each mask pattern can also be set according to user needs, and the present disclosure does not limit this.

[0047] return Figure 2 At block 204, the electronic device 120 may acquire a plurality of light source patterns (eg, a first light source pattern S1, a second light source pattern S2, ..., a Jth light source pattern S J), respectively as a plurality of initial light source patterns. In some embodiments, a plurality of light source patterns are generated based on the set of mask patterns 110. In some embodiments, a 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 (eg, a first light source pattern S1, a second light source pattern S2, ..., a Jth light source pattern S3) based on the received set of mask patterns 110. J ), and the generated multiple light source graphics are used as multiple initial light source graphics for subsequent optimization processing.

[0049] In some other embodiments, the electronic device 120 may receive multiple light source patterns as initial light sources. In this case, multiple light source patterns (e.g., the first light source pattern S1, the second light source pattern S2, ..., the Jth light source pattern S3) may be generated based on the set of mask patterns 110 by other electronic devices different from the electronic device 120 (e.g., any electronic device among the first electronic device 130, the first optimization electronic device 160-1, ..., the Mth optimization electronic device 160-M). J ). Other electronic devices that generate multiple light source patterns can send the generated multiple light source patterns to the electronic device 120, so that the electronic device 120 can obtain the multiple light source patterns and use the obtained multiple light source patterns as multiple initial light sources for subsequent optimization processing.

[0050] A specific implementation of generating a light source pattern 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 a plurality of light source patterns (eg, a first light source pattern S1, a second light source pattern S2, ..., a Jth light source pattern S J ) in each light source graphic S 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 group of mask patterns 110 G i , the electronic device 120 can iteratively update the light source mask pattern combination G i Each light source graphic S in i and the set of mask patterns 110 .

[0052] In some embodiments, the light source mask pattern combination G i Includes light source graphics S i And the group of mask patterns 110. That is, the light source mask pattern combination Gi Includes light source graphics S i , a first mask pattern 110-1, a second mask pattern 110-2, ... an Nth mask pattern 110-N. Specifically, the first light source mask pattern combination G 1 The second light source mask pattern combination may include a first light source pattern S1, a first mask pattern 110-1, a second mask pattern 110-2, ..., an Nth mask pattern 110-N. G 2 The second light source pattern S2, the first mask pattern 110-1, the second mask pattern 110-2, ... the Nth mask pattern 110-N, and so on, and the Jth light source mask pattern combination G J The Jth light source pattern S may be included J , a first mask pattern 110-1, a second mask pattern 110-2, ... an Nth 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 generate a mask pattern combination for all light sources. G 1 ~ G J Furthermore, the electronic device 120 may perform an iterative update process for each light source mask pattern combination. G i Perform iterative update operations independently.

[0054] Alternatively, to increase the optimization speed, Figure 1 The first optimized electronic device 160-1, ..., the Mth optimized electronic device 160-M (as shown in Figure 1 ) independently optimize one or more light source mask pattern combinations G i , where M≤J. In this case, the first optimization electronic device 160-1, ..., and the Mth optimization electronic device 160-M can respectively receive the group of mask patterns 110, and respectively obtain one or more light source patterns (for example, they can be generated based on the received group of mask patterns 110, or the corresponding light source patterns can be received from the electronic device 120 or the first electronic device 130) for subsequent iterative 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 consisting of each acquired light source pattern and the group of mask patterns 110.

[0055] For example, the first optimization electronic device 160-1 may receive the second light source pattern S2 and the group of mask patterns 110, and for 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 optimization electronic device 160-M may receive the (J-1)th light source pattern S （J-1） and the group of mask patterns 110, and for the (J-1)th light source pattern S （J-1） , a first mask pattern 110-1, a second mask pattern 110-2, ..., a light source mask pattern combination of an Nth mask pattern 110-N G (J-1) The Mth optimization electronic device 160-M may also receive the Jth light source pattern S J and the group of mask patterns 110, and for the J-th light source pattern S J , a first mask pattern 110-1, a second mask pattern 110-2, ..., a light source mask pattern combination of an Nth mask pattern 110-N G J Perform iterative update processing.

[0056] In some embodiments, each of the electronic devices 120, the first optimization electronic device 160-1, ..., and the Mth optimization electronic device 160-M can independently perform iterative update operations. That is, for multiple light source mask pattern combinations corresponding to multiple light source patterns, the electronic device 120, the first optimization electronic device 160-1, ..., and the Mth optimization electronic device 160-M can independently iteratively update each light source mask pattern combination in the multiple light source mask pattern combinations.

[0057] The following describes the combination of mask patterns for multiple light sources. G 1 ~ G J Each light source mask pattern combination in G i (where 1≤i≤J; i is a positive integer; J represents the number of light source patterns), the electronic device (the electronic device 120, the first optimized electronic device 160-1, ..., any electronic device of the Mth optimized electronic device 160-M) combines the light source mask pattern G i The specific process of iterative updating.

[0058] The electronic device 120 will still be used as an example for description below, but it can be understood that any device that performs iterative update (the electronic device 120, the first optimization electronic device 160-1, ..., any electronic device in the Mth optimization electronic device 160-M) can perform similar operations described below to implement iterative update operations on corresponding light source mask pattern combinations. In addition, the iterative update operations described below are applicable to each light source mask pattern combination.

[0059]

[0060] in, Pixels in the wafer pattern The pixel value at , and is the pixel point in the target mask pattern P is the number of pixels in the graph.

[0061] In addition, it is understandable that the loss function cost can also include other metrics that are of concern to the lithography process, such as edge placement error (EPE), normalized light intensity logarithmic slope (NILS), process window (PW), etc. Based on different metrics, the light source mask pattern combination can be G i A corresponding loss function is set, which is not limited in this disclosure.

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

[0063] Figure 4 A flowchart of a gradient-based iterative optimization method 400 according to an embodiment of the present disclosure is shown. The flowchart of the method 400 can be represented by Figure 1 The electronic device 120, the first optimized electronic device 160-1, ..., any electronic device in the Mth optimized electronic device 160-M is executed. The electronic device 120 will be taken as an example for description below. In addition, the numbers in the flowchart do not indicate the order in which these steps are executed. 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 may determine a light source pattern to be optimized and a set of mask patterns to be optimized. G i The electronic device 120 may 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 (eg, the loss function has converged) 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, which is not limited in the present disclosure. The present disclosure takes the steepest descent method as an example to illustrate the operation process of the electronic device 120 updating the light source pattern and the mask pattern.

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

[0069] in, S k+1 and S k Represents the light source graphics of the (k+1)th iteration and the kth iteration, M (k+1;j) and M (k;j) represents: the j-th mask pattern in 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.

[0070] 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 round of iteration, the electronic device 120 may update the light source pattern and each mask pattern based on the first gradient matrix , iteratively update the light source graphics, and based on the second gradient matrix , iteratively updating each mask pattern in a set of mask patterns. At block 406, the electronic device 120 may determine whether the iterative updating operation satisfies a termination condition.

[0071] In response to the iterative update operation not satisfying the termination condition, the 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) If the loss function converges or the number of iterations or iteration updates has reached a preset threshold, the process 400 enters block 410, where the electronic device 120 can update the light source pattern 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 iterative result R .

[0072] In some embodiments, for the light source mask pattern combination G i After q rounds of iterative update operations, the electronic device 120 can obtain the corresponding iterative result R i , the iterative result R i The updated light source graphics after q rounds of iterations are included S (i;q) and mask pattern M (i;q;1) , M (i; q;2) ,……, M (i; q;N)。

[0073] In some embodiments, the electronic device 120 may perform the iterative operation described above to S 1 ~ S J The corresponding light source mask pattern combinations G 1 ~ G J Perform iterative update processing and obtain corresponding iterative results. For example, for the light source mask pattern combination G 1 After t rounds of iterative update operations, the electronic device 120 can obtain the corresponding iterative result R 1 , the iterative result R 1 The updated light source graphics after t rounds of iterations are includedS (1;t) and 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 undergoes b rounds of iterative update operations, the corresponding iterative result R J , the iterative result R i The light source graphics updated after round b of iterations are included S (J;b) and mask pattern M (J; b;1) , M (J; b;2) ,……, M (J; b;N)。

[0074] In addition, when an iterative update process is performed on the light source mask pattern combination by an optimization electronic device different from the electronic device 120 (for example, the first optimization electronic device 160-1, ..., the optimization electronic device in the Mth optimization electronic device 160-M), the corresponding optimization 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.

[0075] Back to Figure 2 At block 208, the electronic device 120 may determine 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.

[0076] In some embodiments, the electronic device may 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 may 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 a set of iteratively updated mask patterns in the target light source mask pattern combination as the optimized mask pattern.

[0077] In some embodiments, the electronic device may perform a lithography performance evaluation on the iteratively updated light source mask pattern combination based on the values ​​of multiple groups of metric indicators corresponding to multiple iteratively updated light source mask pattern combinations. In some embodiments, the electronic device may perform a cost and / or efficiency evaluation on the iteratively updated light source mask pattern combination, and based on the evaluation results, select a target light source mask pattern combination from multiple iteratively updated light source mask pattern combinations to determine an optimized light source pattern and an optimized mask pattern. In addition, according to actual needs, the electronic device may also perform other evaluations on the iteratively updated light source mask pattern combination, and select a target light source mask pattern combination based on the evaluation results to determine an optimized light source pattern and an optimized mask pattern.

[0078] The following will be explained by taking an 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 light source mask pattern combinations. The electronic device 120 can determine the values ​​of multiple groups of metric indicators corresponding to multiple iteratively updated light source mask pattern combinations based on the iteration results R corresponding to the multiple iteratively updated light source mask pattern combinations. The electronic device 120 can select a target light source mask pattern combination from multiple iteratively updated light source mask pattern combinations based on the values ​​of multiple groups of metric indicators corresponding to the multiple iteratively updated light source mask pattern combinations. In some embodiments, the metric includes at least one of the following items: edge placement error, normalized light intensity logarithmic slope, and process window.

[0079] In some embodiments, the electronic device 120 may determine the group of light source mask pattern combinations according to the iteration result R obtained at block 206. G i The value of the metric after the above iterative update operation MTR i For example, the electronic device 120 may determine the iteration result R i The edge placement error associated with each mask pattern in the iteratively updated light source pattern, the normalized light intensity logarithmic slope associated with the iteratively updated light source pattern, and the process window associated with the iterative result.

[0080] For multiple groups of light source mask pattern combinations, the electronic device 120 can obtain the values ​​of the metric indicators corresponding to the multiple groups of light source mask pattern combinations. For example, the electronic device 120 can generate the value of the corresponding metric indicator based on the iteration result. Alternatively, the electronic device 120 can receive the value of the corresponding metric indicator from the electronic device that generates the iteration result, which is not limited in the present disclosure.

[0081] The electronic device 120 may select a target light source mask pattern combination from a plurality of iteratively updated light source mask pattern combinations according to the values ​​of the plurality of sets of metric indicators obtained. For example, the electronic device 120 may select a light source mask pattern combination corresponding to a value of a metric indicator that meets the requirements as the target light source mask pattern combination according to a reference value or a range of reference values ​​set by a user.

[0082] In some embodiments, the smaller the EPE value, the better. Preferably, the EPE is less than 1.0 nm. The larger the NILS value, the better. Preferably, the NILS is greater than 1.0 nm. The larger the depth of focus (DOF) of the process window, the better. The requirements of different process nodes are different. Preferably, at an exposure latitude (EL) of 5%, the DOF is greater than 80 nm or 100 nm.

[0083] 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 pattern 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 based on the values ​​of a set of metrics (such as EPE, NILS, DOF, etc.). The present disclosure does not limit the number of selected mask patterns, and the user can select an appropriate number of iterated mask patterns according to needs.

[0084] The implementation manner in which the electronic device evaluates multiple iteratively updated light source mask pattern combinations in other aspects may be similar to the principle of the implementation manner for the above lithography performance evaluation or implemented in any appropriate manner, which is not limited in the present disclosure.

[0085] According to the scheme for light source mask optimization proposed in the embodiment of the present disclosure, by using multiple initial light sources for optimization, light source patterns and mask patterns that meet the requirements can be selected from multiple groups of optimization results as target optimization results, thereby reducing the probability of optimization falling into a local optimal solution and increasing the probability of obtaining optimization results that meet the requirements. At the same time, according to the scheme for light source mask optimization in the embodiment of the present disclosure, multiple initial light source patterns are generated based on the optical diffraction characteristics of the target mask pattern, so that 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 source can have better imaging performance, and thus, can provide a significantly increased process window.

[0086] In some embodiments, the light source mask optimization method according to the embodiment of the present disclosure may further include: generating, by the electronic device 120 or another electronic device different from the electronic device 120 (for example, the first electronic device 130, the first optimization electronic device 160-1, ..., an electronic device in the optimization electronic device in the Mth optimization electronic device 160-M) a plurality of light source graphics (for example, the first light source graphic S1, the second light source graphic S2, ..., the Jth light source graphic S J ), respectively as a plurality of initial light source patterns. In some embodiments, the plurality of light source patterns are different from each other. The specific implementation process of the electronic device (electronic device 120 or other electronic device) generating a plurality of light source patterns based on a received set of mask patterns 110 will be described in detail below.

[0087] For the sake of simplicity, the following description will be made by taking the electronic device 120 as an example. Those skilled in the art can understand that other electronic devices different from the electronic device 120 (for example, the first electronic device 130, the first optimized electronic device 160-1, ..., the electronic device in the optimized electronic device in the Mth optimized electronic device 160-M) can also perform similar operations to generate multiple light source patterns. Figure 5 A flow chart of a method 500 for generating a plurality of light source patterns based on a set of mask patterns according to an embodiment of the present disclosure is shown.

[0088] In block 502, the electronic device 120 may obtain pattern information of each target mask pattern in a set of mask patterns. In some embodiments, the set of mask patterns is a mask pattern group 110 received by the electronic device 120 in the method 200 and used for iterative processing, and the set of mask patterns includes a first mask pattern 110-1, a second mask pattern 110-2, ..., an 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, i.e., target patterns that are expected to be imaged on a wafer through a photolithography process. Figures 3A-3D An example of a plurality of target mask patterns in the group of mask patterns 110 is schematically shown. Each schematic target mask pattern has been described in detail above, and for the sake of brevity, it will not be described again here.

[0089] 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 of the target mask pattern 110-n within the polygon to 1 and the pixels of the target mask pattern 110-n outside the polygon to 0, thereby generating a mask matrix M for the target mask pattern 110-n. maskn .

[0090] In some embodiments, the electronic device 120 may maskn Perform Fourier transform to obtain the mask matrix M maskn The corresponding complex matrix Mc n , and the complex matrix Mc n Indicates the spectrum information of the corresponding target mask pattern 110 - n.

[0091] In some embodiments, the mask matrix M maskn By performing Fourier transform, the diffraction spectrum of the target mask pattern can be obtained. Accordingly, the complex matrix Mc corresponding to the target mask pattern 110-i is n Indicates the spectrum information of the corresponding target mask pattern 110 - n.

[0092] In some embodiments, the electronic device 120 may generate a complex matrix M corresponding to each target mask pattern 110 - n acquired in block 502. cn Convert to real matrix M rn In some embodiments, the electronic device may convert the complex matrix M cn Each element in is modulo, and each matrix obtained after modulo is used as the matrix with the complex matrix M cn The corresponding real matrix M rn In some embodiments, the real number matrix M rn Indicates pattern information of the target mask pattern 110 - n .

[0093] 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 acquired in block 502 .

[0094] The following will be combined Figure 6 A specific implementation method for determining a light source pattern corresponding to each target mask pattern is described. Figure 6FIG. 6 is a flowchart of a method 600 for determining a light source pattern corresponding to a target mask pattern based on pattern information of a target mask pattern according to an embodiment of the present disclosure. Figure 6 It is understood by those skilled in the art that Figure 1 Other electronic devices in the light source mask optimization system 104 can also perform similar operations to generate multiple light source patterns. Figure 6 The method 600 in the embodiment is to determine or generate a light source pattern corresponding to a target mask pattern in a set of mask patterns. Figure 6 The method 600 in the embodiment is used to generate a corresponding light source graphic.

[0095] In block 602, the electronic device 120 may determine a real number matrix M corresponding to the target mask pattern 110-n. rn In some embodiments, the electronic device 120 may determine the maximum value of the elements among multiple elements (eg, all elements) in the real number matrix. For example, taking a 5×5 real number matrix as an example, the electronic device may determine the maximum value max among the 25 elements in the 5×5 matrix. signal .

[0096] The electronic device 120 may also determine the number of elements pixel of a plurality of elements (eg, all elements) in the real number matrix. num Furthermore, the electronic device 120 may sum the values ​​of multiple elements (eg, all elements) in the real number matrix and obtain the sum value signal sum The electronic device 120 can calculate and signal sum 、The maximum value of the element max signal And the number of elements pixel num , to determine the pupil filling rate PFR of the real number matrix. In some embodiments, the electronic device 120 can determine the pupil filling rate PFR according to formula (7):

[0097] return Figure 6 In block 604, the electronic device 120 determines a comparison of the pupil filling rate PFR determined in block 602 with a pupil filling rate threshold. In some embodiments, the pupil filling rate threshold indicates a minimum PRF and may be pre-set.

[0098] In response to the pupil filling rate PFR being greater than the pupil filling rate threshold, the process of the method 600 enters box 622. In box 622, the electronic device 120 normalizes the real number matrix. In box 624, the electronic device 120 determines the 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 may correspond to the intensity of each pixel in the light source pattern to be generated. The electronic device 120 may generate the light source pattern based on the corresponding relationship.

[0099] In some embodiments, in response to the pupil filling rate PFR not being greater than the pupil filling rate threshold, the process of method 600 enters box 612. In box 612, the electronic device 120 can perform fuzzy processing on the real number matrix. Each time the fuzzy processing is performed, the electronic device 120 compares the pupil filling rate of the real number matrix after the fuzzy processing with the pupil filling rate threshold at box 604. The electronic device 120 can calculate the pupil filling rate for the real number matrix after the fuzzy processing in the manner described above. In response to the pupil filling rate not being greater than the pupil filling rate threshold, the electronic device 120 continues to perform fuzzy processing on the real number matrix at box 612 until the pupil filling rate of the real number matrix is ​​greater than the pupil filling rate threshold.

[0100] The following will describe the implementation process of fuzzy processing on a real number matrix with reference to the accompanying drawings. Figure 7 The following is a schematic implementation process of performing fuzzy processing on a real number matrix according to an embodiment of the present disclosure. Figure 7 The real number matrix M1 in represents the matrix after the real number matrix M is fuzzy processed. Figure 7 The values ​​of the matrix elements in are only indicative. And, Figure 7 Taking a 5×5 matrix as an example, it can be understood that Figure 7 The implementation of the blur operation in can be used for matrices of any size.

[0101] In the process of performing fuzzy processing on the real number matrix M, the electronic device 120 may determine the elements to be allocated in the real number matrix. In some embodiments, the elements to be allocated may be elements with larger element values ​​in the matrix. For example, the electronic device 120 may select the element with the largest value in the current matrix as the element to be allocated in each fuzzy processing. Figure 7 Take the matrix M in as an example, the maximum value of the elements in the current matrix is ​​the element a in the 3rd row and 1st column 31 and the element a in row 2, column 4 24 In a fuzzy process, the electronic device 120 may select element a 31 and a 24 Any element in is used as the element to be assigned.

[0102] 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 case where the selected 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.

[0103] 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 be along 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 selected element to be assigned is element a 24 When the electronic device 120 can be along 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 multiple 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 .

[0104] It is understandable that the above examples are only illustrative. The electronic device 120 may select multiple elements in the second direction to assign values ​​of the elements to be assigned, and the values ​​assigned to each element are not necessarily equal.

[0105] 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 is shown. It can be seen that by performing blurring on the real number matrix, the image generated based on the blurring matrix can be made uniform and smooth.

[0106] As described above, the electronic device 120 may 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.

[0107] Figure 9A-9C A schematic diagram of three light source patterns generated according to an embodiment of the present disclosure is shown. It is understandable that this is only illustrative, and those skilled in the art can obtain a light source pattern of any shape related to a target mask pattern according to the principles disclosed in the embodiment of the present disclosure.

[0108] Fig.9D Schematic diagram showing the light source pattern of the diode illumination. For a one-dimensional line in the vertical direction (such as Figures 3A-3D The main graphic in Fig.9D The horizontal diode illumination is shown in FIG. Fig.9D When the light source mask is optimized by using the light source pattern of the diode illumination shown in , the range of the depth of focus (DOF) of the optimal lithography process window is usually less than 270nm. Figures 9A-9C ), the depth of focus (DOF) of the optimal lithography process window is close to 300nm. It can be seen that the lithography process window is significantly expanded by adopting the light source mask optimization solution according to the embodiment of the present disclosure.

[0109] Fig.10 1 is a schematic block diagram of an example device 1000 that can be used to implement an embodiment of the present disclosure. The device 1000 can be used to implement Figure 1 Any electronic device among the electronic device 120, the first electronic device 130, the first optimized electronic device 160-1, ..., the Mth optimized electronic device 160-M. Fig.10As shown, the 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 loaded from a storage unit 1008 to 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.

[0110] A number of 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 disk, an optical disk, 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 through a computer network such as the Internet and / or various telecommunication networks.

[0111] The processing unit 1001 performs 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, which are tangibly contained in a machine-readable medium, such as storage unit 1008. In some embodiments, part or all of the computer program can be loaded and / or installed on the device 1000 via ROM 1002 and / or communication unit 1009. When the computer program is loaded into RAM 1003 and executed by the processing unit 1001, one or more steps of the methods 200, method 400, method 500, and method 600 described above can be performed. Alternatively, in other embodiments, the processing unit 1001 can be configured to perform methods 200, method 400, method 500, and method 600 in any other appropriate manner (for example, by means of firmware).

[0112] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chip systems (SOCs), load programmable logic devices (CPLDs), and the like.

[0113] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0114] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0115] In addition, although each operation is described in a specific order, this should be understood as requiring such operation to be performed in the specific order shown or in a sequential order, or requiring that all illustrated operations should be performed to obtain desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination mode.

[0116] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions 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; Acquire a plurality of light source patterns to serve as a plurality of initial light source patterns respectively, wherein the plurality of light source patterns are generated based on the set of mask patterns; For each light source mask pattern combination formed by each light source pattern in the plurality of light source patterns and the group of mask patterns, iteratively updating each light source pattern and the group of mask patterns in each light source mask pattern combination to obtain an iteratively updated light source mask pattern combination; as well as An optimized light source pattern and an optimized mask pattern are determined based on a plurality of iteratively updated light source mask pattern combinations respectively corresponding to the plurality of light source patterns.

2. The method according to claim 1, wherein acquiring a plurality of light source patterns to serve as a plurality of initial light source patterns comprises: Based on the set of mask patterns, the plurality of light source patterns are generated to serve as the plurality of initial light source patterns respectively.

3. The method of claim 2, wherein the set of mask patterns comprises a plurality of target mask patterns, and wherein generating the plurality of light source patterns comprises: For each target mask pattern in the plurality of target mask patterns: Acquiring pattern information of each target mask pattern; as well as Based on the pattern information, a light source pattern corresponding to each target mask pattern is determined.

4. The method according to claim 3, wherein: Acquiring the pattern information of each target mask pattern includes: generating a mask matrix corresponding to each of the target mask patterns; and Performing Fourier transformation on the mask matrix to obtain a complex matrix corresponding to the mask matrix, wherein the complex matrix indicates frequency spectrum information of each target mask pattern; and The complex number matrix corresponding to each of the target mask patterns is converted into a real number matrix, wherein the real number matrix indicates the pattern information of each of the target mask patterns.

5. The method according to claim 4, wherein determining the light source pattern corresponding to each target mask pattern based on the pattern information comprises: Determining a pupil filling rate of the real matrix; In response to the pupil filling rate being greater than a pupil filling rate threshold, normalizing the real number matrix; as well as Based on the normalized real number matrix, the light source pattern corresponding to each target mask pattern is determined.

6. The method according to claim 4, wherein determining the light source pattern corresponding to each target mask pattern based on the pattern information comprises: determining a pupil filling factor of the real number matrix; In response to the pupil filling rate being not greater than a pupil filling rate threshold, iteratively performing fuzzy processing on the real number matrix until the pupil filling rate of the real number matrix is ​​greater than the pupil filling rate threshold; as well as Based on the real number matrix after iterative fuzzy processing, the light source pattern corresponding to each target mask pattern is determined.

7. The method of claim 6, wherein iteratively blurring the real number matrix comprises: During each iteration: Determine the elements to be allocated in the real number matrix; Determining a first direction between the element to be allocated and a central element of the real number matrix; as well as Along a second direction perpendicular to the first direction, the value of the element to be allocated is at least partially 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 comprises: Determine the maximum value of an element among a plurality of elements in the real number matrix; Determining the number of elements of the plurality of elements in the real number matrix; determining a sum of element values ​​of the plurality of elements; as well as The pupil filling rate of the real number matrix is ​​determined based on the sum of the element values, the element maximum value, and the number of elements.

9. The method according to claim 1, wherein determining an optimized light source pattern and an optimized mask pattern comprises: evaluating the plurality of iteratively updated light source mask pattern combinations; as well as Based on the evaluation result, a target light source mask pattern combination is selected from the plurality of iteratively updated light source mask pattern combinations to determine an optimized light source pattern and an optimized mask pattern.

10. The method of claim 9, wherein determining an optimized light source pattern and an optimized mask pattern comprises: Using the iteratively updated light source pattern in the target light source mask pattern combination as the optimized light source pattern; as well as At least one mask pattern in the set of iteratively updated mask patterns in the target light source mask pattern combination is used as the optimized mask pattern.

11. The method according to claim 9, wherein evaluating the plurality of iteratively updated light source mask pattern combinations comprises: Based on the values ​​of the multiple groups of metric indicators respectively corresponding to the multiple iteratively updated light source mask pattern combinations, the lithography performance of the iteratively updated light source mask pattern combination is evaluated. 12 . The method of claim 11 , wherein each set of metric indicators in the plurality of sets of metric indicators comprises at least one of the following: edge placement error, normalized intensity logarithmic slope, 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 comprises: Determine a first gradient matrix of the loss function of the light source mask pattern combination with respect to the light source pattern; Determining a second gradient matrix of the loss function for the set of mask patterns; as well as During each iteration: Based on the first gradient matrix, updating the light source graphic; as well as Based on the second gradient matrix, each mask pattern in the set of mask patterns is updated.

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

15. An electronic device, comprising: one or more processors; as well as A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to execute the method as described in any one of claims 1 to 14.

16. A computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the method according to any one of claims 1 to 14 when executed by a processor.

17. A computer program product, comprising a program code, wherein when the program code is executed by a processor, the method according to any one of claims 1 to 14 is implemented.

Images