Optical proximity correction method of one-dimensional pattern, storage medium and electronic equipment

Abstract

The invention provides an optical proximity correction method for a one-dimensional pattern, a storage medium and electronic equipment, and the method comprises the steps: building a model error table of one-dimensional patterns of various sizes in various space environments, and enabling the model error table to be obtained through a numerical value compensation table and a model compensation table, the numerical value complement table is obtained by correcting a one-dimensional pattern of each size in each space environment based on a rule optical proximity effect, and the model complement table is obtained by correcting a one-dimensional pattern of each size in each space environment based on a model optical proximity effect; and performing rule-based optical proximity correction on the one-dimensional pattern, the rule including the numerical value complement table, and then performing model-based optical proximity correction, the model including the model error table as a correction parameter. The method can be used for optimizing the optical proximity correction of the one-dimensional pattern.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit manufacturing, and in particular to an optical proximity correction method, storage medium, and electronic equipment for a one-dimensional pattern. Background Art

[0002] In the photolithography process, the graphic structure corresponding to the layout on the mask will be projected into the photoresist through the exposure system and form the corresponding graphic structure in the photoresist. However, due to optical reasons in the exposure process (such as diffraction effect) or chemical reactions of the photoresist, there is a deviation between the graphic structure formed in the photoresist and the graphic structure on the mask. This deviation requires the layout on the mask to be modified in advance through OPC (Optical Proximity Correction). When the mask corrected by OPC is used for exposure, the graphic structure formed in the photoresist will be consistent with the designed graphic structure and meet the process production requirements.

[0003] As the feature size of integrated circuits continues to decrease, model-based optical proximity correction has become the mainstream of mask correction. Even for one-dimensional patterns, model-based optical proximity correction is an indispensable step. Therefore, the above optical proximity correction is extremely time-consuming and resource-consuming. Therefore, how to reduce the time of OPC correction and improve the accuracy of OPC correction is extremely important. Summary of the invention

[0004] The object of the present invention is to provide an optical proximity correction method, a storage medium, and an electronic device for optimizing the optical proximity correction of a one-dimensional pattern.

[0005] In order to solve the above technical problems, the present invention provides an optical proximity correction method for a one-dimensional pattern, comprising:

[0006] Establishing a model error table for one-dimensional patterns of various sizes in various spatial environments, wherein the model error table is obtained from a numerical value supplement table and a model supplement table, wherein the numerical value supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on rules, and the model supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on models;

[0007] A rule-based optical proximity effect correction is performed on the one-dimensional pattern, and then a model-based optical proximity effect correction is performed, wherein the rule includes the numerical value supplement table, and the model includes the model error table as a correction parameter.

[0008] Optionally, the spatial environment of the one-dimensional pattern includes a distance between the centers of adjacent patterns and the number and arrangement of sub-resolution auxiliary patterns disposed between adjacent patterns.

[0009] Optionally, multiple sizes and multiple spatial environments of the one-dimensional pattern are formulated according to the design rules, and the multiple sizes cover all important size settings on the photoresist layer, and the multiple spatial environments cover all important spatial settings on the photoresist layer.

[0010] Optionally, the step of obtaining the numerical value supplement table includes:

[0011] Obtaining first MEEF values ​​of one-dimensional patterns of different sizes based on rule-based optical proximity effect in various spatial environments, wherein one-dimensional patterns of various sizes in the same spatial environment have the same or similar first MEEF values;

[0012] According to the various spatial environments and the corresponding first MEEF values, the first mask sizes of one-dimensional patterns of different sizes in various spatial environments are obtained as the numerical value supplement table.

[0013] Optionally, the step of obtaining the model supplement value table includes:

[0014] Obtaining the second MEEF values ​​of the optical proximity effect based on the model of the one-dimensional patterns of different sizes in each spatial environment, so that the one-dimensional patterns of different sizes in the same spatial environment have the same or similar second MEEF values;

[0015] According to the various spatial environments and the corresponding second MEEF values, the second mask sizes of the one-dimensional patterns of different sizes in the various spatial environments are obtained as the model supplement value table.

[0016] Optionally, the model error table is obtained by subtracting the numerical value supplement table and the model supplement table under the same target size and the same spatial environment.

[0017] Optionally, when performing rule-based optical proximity effect correction on a one-dimensional pattern, parameters of the spatial environment and size corresponding to the one-dimensional pattern to be corrected are obtained from the numerical compensation table, and a correction is performed once using the entire edge line segment of the one-dimensional pattern as a correction unit as preprocessed layout data.

[0018] Optionally, when performing the first correction of the model-based optical proximity correction on the one-dimensional pattern, the corresponding parameters in the model error table are used as correction parameters to correct the layout data based on the preprocessing, and the corrected regression parameters are reduced at the same time.

[0019] According to another aspect of the present invention, a storage medium is further provided, wherein the storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor to execute the optical proximity correction method as described above.

[0020] Based on another aspect of the present invention, an electronic device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the optical proximity correction method as described above when executing the computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art should understand that the drawings are provided for a better understanding of the present invention, but do not constitute any limitation on the scope of the present invention.

[0022] Figure 1 is a flow chart of an optical proximity correction method for a one-dimensional pattern provided in an embodiment of the present application;

[0023] Figure 2 A flow chart of a method for obtaining a numerical value supplement table provided in this application;

[0024] Figure 3 It is a schematic diagram of a numerical value supplement table;

[0025] Figure 4 A flow chart of the method for obtaining a model supplement table provided in this application;

[0026] Figure 5 It is a schematic diagram of a one-dimensional pattern in an embodiment of the present application.

[0027] In the accompanying drawings: 10 - one-dimensional pattern; 11 - middle section; 12 - end section. DETAILED DESCRIPTION

[0028] As described in the background technology, for a single one-dimensional pattern, the corresponding OPC model meets the modeling error specifications when it is established (after establishment) and also meets the design requirements. However, when the one-dimensional pattern is placed on the layout, the error range generated by the corresponding OPC model will be expanded, which not only affects the accuracy of the OPC correction, but also consumes additional time for the OPC correction. The inventors have found that the above situation is because the OPC model is affected by the spatial environment around the one-dimensional pattern on the layout, making the OPC model inaccurate. Among them, the spatial environment around the one-dimensional pattern may include, for example, the spacing distance between adjacent patterns, the number and setting method of sub-resolution auxiliary patterns between adjacent patterns, etc.

[0029] To this end, the present application provides an optical proximity correction method for a one-dimensional pattern, a storage medium, and an electronic device, the optical proximity correction method comprising: establishing a model error table for a one-dimensional pattern of each size under each spatial environment, the model error table being obtained by a numerical complement table and a model complement table, the numerical complement table being obtained by a rule-based optical proximity effect correction for a one-dimensional pattern of each size under each spatial environment, the model complement table being obtained by a model-based optical proximity effect correction for a one-dimensional pattern of each size under each spatial environment; performing a rule-based optical proximity effect correction on the one-dimensional pattern, and then performing a model-based optical proximity effect correction, the rule comprising the numerical complement table, and the model comprising the model error table as a correction parameter. In the present application, the above rule is obtained by performing correction simulation on a one-dimensional pattern of each size under each spatial environment, the rule taking into account the influence of different spatial environments and each size on the correction, and before performing a model-based correction on the one-dimensional pattern, the rule is used to perform a correction similar to preprocessing on the one-dimensional pattern, and the accuracy of a part of the area is improved by one correction, which can save time and resources for subsequent model-based optical proximity correction. Similarly, after obtaining the model compensation table and the model error table, when performing model-based corrections, the parameters of the corresponding dimensions and spatial environment are also obtained from the model error table to correct the corrected data, thereby reducing the regression parameters during correction while ensuring accuracy and reducing the execution time of the correction script.

[0030] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0031] As used in the present invention, the singular forms "one", "an", and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second", and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features, unless the content clearly indicates otherwise.

[0032] Figure 1 It is a flow chart of the optical proximity correction method of a one-dimensional pattern provided in an embodiment of the present application.

[0033] like Figure 1 As shown, the optical proximity correction method of a one-dimensional pattern provided in this embodiment includes the following steps:

[0034] S01: establishing a model error table for one-dimensional patterns of various sizes in various spatial environments, wherein the model error table is obtained from a numerical value supplement table and a model supplement table, wherein the numerical value supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on rules, and the model supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on models;

[0035] S02: performing rule-based optical proximity effect correction on the one-dimensional pattern, and then performing model-based optical proximity effect correction, wherein the rule includes the numerical value supplement table, and the model includes the model error table as a correction parameter.

[0036] First, execute step S01 to establish a model error table for one-dimensional patterns of various sizes in various spatial environments. The model error table is obtained by a numerical compensation table and a model compensation table. The numerical compensation table is obtained by correcting the optical proximity effect of the one-dimensional patterns of various sizes in various spatial environments based on rules. The model compensation table is obtained by correcting the optical proximity effect of the one-dimensional patterns of various sizes in various spatial environments based on models.

[0037] One-dimensional pattern can be a strip-shaped figure extending in a straight line or the space between adjacent strip-shaped figures. In the present application, one-dimensional pattern can be a strip-shaped figure extending in a straight line, and the above-mentioned various dimensions and various spatial environments are all dimensions on the photoresist, that is, the dimensions (i.e., target dimensions) as the design target. Moreover, multiple dimensions and multiple spatial environments of one-dimensional pattern for establishing a model error table can also be formulated according to design rules, so that the above-mentioned multiple dimensions cover all important dimension settings on the photoresist layer, and the above-mentioned multiple spatial environments cover all important spatial settings on the photoresist layer. In other words, after the model error table is established, the data corresponding to the common target size and spatial environment can be obtained by consulting the above-mentioned model error table. Wherein, the spatial environment of the one-dimensional pattern can also include the number and setting mode of the sub-resolution auxiliary patterns located between the adjacent patterns in addition to the center spacing distance between the adjacent patterns. For one-dimensional patterns of the same size and the same spacing distance, if the number, size or setting mode (arrangement mode) of the sub-resolution auxiliary patterns around the one-dimensional pattern changes, it is also regarded as different spatial environments. Of course, on the other hand, in the same spatial environment, the intervals between one-dimensional patterns of different sizes are different, and the parameters of the one-dimensional pattern are also different.

[0038] Figure 2 This is a flow chart of the method for obtaining a numerical value supplement table provided in this application. Figure 2 As shown, the steps of obtaining the numerical value supplement table include:

[0039] S011: Obtaining the first MEEF value of the optical proximity effect based on the rule for one-dimensional patterns of different sizes in each spatial environment. The step of obtaining the first MEEF value may, for example, include: firstly, a range space of data to be collected may be prepared, including the above-mentioned multiple target sizes covering all important size settings on the photoresist and multiple spatial environments of all important spatial settings, and then, according to the above-mentioned range space, a simulation of optical proximity correction based on the rule is performed to obtain the mask size required to form the one-dimensional pattern of each target size in each spatial environment, and the MEEF value of the one-dimensional pattern of each target size formed in each spatial environment as the first MEEF value, and the MEEF value (i.e., the mask error enhancement factor) may be calculated by dividing the size error on the wafer by the size error on the corresponding mask. Among them, since the number of multiple target sizes and multiple spatial environments involved is large, and the first MEEF values ​​of one-dimensional patterns of different sizes in the same spatial environment are relatively close, in practice, at least one target size simulation may be performed for each spatial environment, and the first MEEF value may be applied to the simulation of multiple target sizes in the spatial environment where it is located. Of course, for particularly important space environments and target sizes, multiple target sizes in the space environment may also be simulated and their MEEF values ​​may be calculated.

[0040] S012: According to each spatial environment and the corresponding first MEEF value, the first mask size of the one-dimensional pattern of different sizes in each spatial environment is obtained as a numerical value complement table. Among them, the established numerical value complement table can be based on the range space of the aforementioned data to be collected, according to the corresponding first MEEF value in each spatial environment, based on the one-dimensional patterns of each size in the same spatial environment have the same or similar first MEEF value, to deduce the mask size required to form the one-dimensional pattern of each target size. That is, the numerical value complement table uses each target size of the one-dimensional pattern as one of the horizontal coordinates or vertical coordinates, and each spatial environment of the one-dimensional pattern as the other of the horizontal coordinates or vertical coordinates. The table content corresponding to (intersecting) the horizontal coordinates and the vertical coordinates is the mask size used to form the one-dimensional pattern of the target size on the mask. Figure 3It is a schematic diagram of the numerical complement table, where the ordinate is the target sizes of the one-dimensional pattern, and the abscissa is the spatial environments of the one-dimensional pattern. The target sizes include, for example, 60nm, 70nm, 80nm, 90nm, 100nm and 120nm, and the center spacing distances of the spatial environments include, for example, 120nm, 130nm, 140nm, 150nm, 160nm, 150nm and 200nm, wherein, for the one-dimensional pattern with a size of 60nm, there is one sub-resolution auxiliary pattern in the center spacing distance of 200nm to 310nm, two sub-resolution auxiliary patterns in the center spacing distance of 310nm to 460nm, three sub-resolution auxiliary patterns in the spacing distance of 460nm to 560nm, and four sub-resolution auxiliary patterns in the spacing distance above 560nm. Of course, due to actual conditions, the number of target sizes is different in different spatial environments.

[0041] Figure 4 This is a flow chart of the method for obtaining the model supplement table provided in this application. Figure 4 As shown, the step of obtaining the model supplementary value table includes: S013: obtaining the second MEEF value of the optical proximity effect of the one-dimensional pattern of different sizes under each spatial environment based on the model; S014: according to each spatial environment and the corresponding second MEEF value, obtaining the second mask size of the one-dimensional pattern of different sizes under each spatial environment as the model supplementary value table. Among them, the range space of the model supplementary value table is the same as the range space of the numerical supplementary value table, and the step of obtaining the model supplementary value table is the same as the step of obtaining the numerical supplementary value table mentioned above. The difference is that when obtaining the model supplementary value table, the optical proximity effect based on the model is simulated to obtain the second MEEF value, and the second MEEF value is only for the size of the middle section of the one-dimensional pattern, not the size of the end section of the one-dimensional pattern. Similarly, when obtaining each second MEEF value for establishing the model supplementary value table, according to the corresponding second MEEF value in each spatial environment, based on the fact that the one-dimensional patterns of each size under the same spatial environment have the same or close second MEEF values, the mask size required to form the one-dimensional pattern of each target size is deduced. Therefore, the table contents corresponding to the horizontal and vertical coordinates in the model compensation table are also the mask size for forming a one-dimensional pattern (middle section) of the target size on the mask, but the mask size is obtained by the optical proximity correction simulation based on the model.

[0042] After obtaining the numerical value supplement table and the model supplement table for one-dimensional patterns of various sizes in various spatial environments, the numerical value supplement table and the model supplement table for the same target size and the same spatial environment can be subtracted to obtain a model error table.

[0043] Next, step S02 is executed to perform rule-based optical proximity effect correction on the one-dimensional pattern, and then perform model-based optical proximity effect correction, where the rule includes a numerical value supplement table and the model includes a model error table as correction parameters.

[0044] For the layout to be corrected, an initial graphic analysis may be performed first, from which a one-dimensional pattern is identified, and the optical proximity correction of the present application is performed on the one-dimensional pattern. The steps of performing the optical proximity correction of the present application may include:

[0045] First, rule-based optical proximity correction can be performed on the one-dimensional pattern and pre-processed layout data can be obtained, and the rule is the aforementioned established numerical complement table. The one-dimensional pattern to be corrected is the same as the one-dimensional pattern to establish the numerical complement table in conditions other than the target size and the spatial environment. In other words, when the numerical complement table is applied to the one-dimensional pattern to be corrected, the two have the same or close first MEEF value under the conditions of the same target size and the same spatial environment. Therefore, the one-dimensional pattern can be conveniently subjected to the rule-based optical proximity correction using the numerical complement table. Moreover, the numerical complement table takes into account the influence of different spatial environments, and can also make the correction have a higher accuracy, so that the accuracy of the pre-processed layout data in a partial area is improved after one correction, which can save time and resources for subsequent model-based optical proximity correction. Figure 5 is a schematic diagram of a one-dimensional pattern. It can be understood that in practice, a one-dimensional pattern is not truly one-dimensional. Figure 5 As shown, the one-dimensional pattern 10 can be divided into a middle section 11 and end sections 12 (a section near the corner) located at both ends of the middle section 11. The above correction can be performed using the entire edge line of the one-dimensional pattern 10 as a correction unit, that is, the optical proximity correction based on the above rule is used to correct the size of the above-mentioned middle section 11 (such as line width).

[0046] Next, the one-dimensional pattern processed as above is subjected to a model-based optical proximity effect correction, and the model includes the model error table established above as a correction parameter. That is, the optical proximity correction based on the model is performed on the pre-processed layout data obtained above. In addition to the conventional model correction, the model-based correction also includes obtaining the parameters of the corresponding size and space environment from the model error table to correct the conventional model correction. The pre-processed layout data is corrected via the conventional model and the model error table, so that the regression parameters during correction can be reduced to reduce the execution time of the correction script while ensuring accuracy. Figure 5For example, when performing model-based optical proximity correction, after the middle segment 11 of the one-dimensional pattern 10 has undergone the aforementioned rule-based correction, the relevant data in the model error table can be applied in the first model-based correction, and the middle segment 11 of the one-dimensional pattern 10 after the aforementioned rule-based correction can be corrected again, thereby improving the acceleration of the correction process and helping to improve the model accuracy. Of course, the above correction parameters cannot directly correct the end segment 12 of the one-dimensional pattern 10, but the end segment 12 is corrected based on the pre-processed middle segment 11 (or the corrected middle segment 11), which is also helpful to accelerate its correction process.

[0047] It should be noted here that since the present application is based on the same and similar MEEF values ​​in the same spatial environment (same center spacing distance and auxiliary graphics), when applying the above-mentioned numerical supplement table, model supplement table and model error table, it is necessary to convert the spacing distance between the one-dimensional patterns into the middle spacing distance of the one-dimensional pattern in combination with its size, and perform table lookup and correction on this basis.

[0048] The present application also provides a computer-readable storage medium, wherein at least one instruction, at least one program, code set or instruction set is stored in the storage medium, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the optical proximity correction method for a one-dimensional pattern provided in the above embodiment. Since the instructions stored in the storage medium can execute the steps in any method provided in the embodiments of the present application, the beneficial effects that can be achieved by any method provided in the embodiments of the present application can be achieved, as detailed in the previous embodiments, which will not be repeated here.

[0049] The present application also provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the optical proximity correction method as described above when executing the computer program.

[0050] In the present application, the above rules are obtained by correcting and simulating one-dimensional patterns of various sizes in various spatial environments. The rules take into account the influence of different spatial environments and various sizes on the correction. Before the one-dimensional pattern is corrected based on the model, the one-dimensional pattern is corrected similar to preprocessing using the rules. The accuracy of some areas can be improved through one correction, which can save time and resources for subsequent model-based optical proximity correction. Similarly, after obtaining the model compensation table and the model error table, when performing model-based correction, the parameters corresponding to the size and spatial environment are also obtained from the model error table to correct the corrected data, so that the regression parameters during correction can be reduced while ensuring accuracy to reduce the execution time of the correction script.

[0051] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. An optical proximity correction method for a one-dimensional pattern, characterized in that: include: Establishing a model error table for one-dimensional patterns of various sizes in various spatial environments, wherein the model error table is obtained from a numerical value supplement table and a model supplement table, wherein the numerical value supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on rules, and the model supplement table is obtained by correcting the optical proximity effect of one-dimensional patterns of various sizes in various spatial environments based on models; A rule-based optical proximity effect correction is performed on the one-dimensional pattern, and then a model-based optical proximity effect correction is performed, wherein the rule includes the numerical value supplement table, and the model includes the model error table as a correction parameter.

2. The optical proximity correction method for a one-dimensional pattern according to claim 1, characterized in that: The spatial environment of the one-dimensional pattern includes the center spacing distance between adjacent patterns, the number and arrangement of sub-resolution auxiliary patterns arranged between adjacent patterns.

3. The optical proximity correction method for a one-dimensional pattern according to claim 1, characterized in that: Multiple sizes and multiple spatial environments of the one-dimensional pattern are formulated according to the design rules, and the multiple sizes cover all important size settings on the photoresist layer, and the multiple spatial environments cover all important spatial settings on the photoresist layer.

4. The optical proximity correction method for a one-dimensional pattern according to claim 2, characterized in that: The step of obtaining the numerical value supplement table comprises: Obtaining first MEEF values ​​of one-dimensional patterns of different sizes based on rule-based optical proximity effect in various spatial environments, wherein one-dimensional patterns of various sizes in the same spatial environment have the same or similar first MEEF values; According to the various spatial environments and the corresponding first MEEF values, the first mask sizes of one-dimensional patterns of different sizes in various spatial environments are obtained as the numerical value supplement table.

5. The optical proximity correction method for a one-dimensional pattern according to claim 2, characterized in that: The step of obtaining the model supplement value table includes: Obtaining the second MEEF values ​​of the optical proximity effect based on the model of the one-dimensional patterns of different sizes in each spatial environment, so that the one-dimensional patterns of different sizes in the same spatial environment have the same or similar second MEEF values; According to the various spatial environments and the corresponding second MEEF values, the second mask sizes of the one-dimensional patterns of different sizes in the various spatial environments are obtained as the model supplement value table.

6. The optical proximity correction method for a one-dimensional pattern according to claim 2, characterized in that: The model error table is obtained by subtracting the numerical value supplement table and the model supplement table under the same target size and the same spatial environment.

7. The optical proximity correction method for a one-dimensional pattern according to claim 1, characterized in that: When performing rule-based optical proximity effect correction on a one-dimensional pattern, parameters of the spatial environment and size corresponding to the one-dimensional pattern to be corrected are obtained from the numerical compensation table, and a correction is performed once using the entire edge line of the one-dimensional pattern as a correction unit as preprocessed layout data.

8. The optical proximity correction method for a one-dimensional pattern according to claim 7, characterized in that: When the first correction of the model-based optical proximity correction is performed on the one-dimensional pattern, the corresponding parameters in the model error table are used as correction parameters to correct the layout data based on the preprocessing, and the regression parameters of the correction are reduced at the same time.

9. A storage medium, characterized in that: The storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor to execute the optical proximity correction method according to any one of claims 1-8.

10. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the optical proximity correction method according to any one of claims 1 to 8 when executing the computer program.

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