Method for setting sub-resolution assist patterns

Abstract

The application provides a method for setting sub-resolution assist pattern. The method comprises the following steps: determining a region capable of being used for setting the assist pattern outside the optimized pattern of the main pattern as a first region, dividing the first region into a plurality of pixels, and setting the initial state of all the pixels in the first region as an unwritten state; setting an initial sub-resolution assist pattern in the first region for the key boundary of the optimized pattern; calculating the evaluation value corresponding to each pixel state of the initial sub-resolution assist pattern by using an OPC model, selecting the pattern corresponding to the pixel state with the minimum evaluation value as an optimal sub-resolution assist pattern; and modifying the state of all the pixels corresponding to the optimal sub-resolution assist pattern to a written state. The setting of the sub-resolution assist pattern can improve the exposure effect of the main pattern and increase the exposure process window.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for setting sub-resolution auxiliary graphics. Background Technology

[0002] For small-sized node products, sub-resolution assistant features (SRAFs) are needed to address the technical issue of the prohibition period pattern process window being too small. SRAFs are small patterns placed around sparse patterns, making the sparse patterns appear as dense patterns from an optical perspective. During exposure, they scatter light, thus increasing the process window.

[0003] Figure 1 This is a schematic diagram of a current sub-resolution auxiliary graphics method. In the prior art, such as... Figure 1 As shown, the sub-resolution auxiliary pattern 11 is generally a long strip structure, or a strip cut into pieces, placed on the side of the main pattern 10 for auxiliary exposure. However, if the critical size of the sub-resolution auxiliary pattern is too small, insufficient scattering will result in the lines of the main pattern being too thin or undercutting, easily leading to peeling problems. If the critical size of the sub-resolution auxiliary pattern is too large, an image will be formed on the photoresist, causing sub-resolution auxiliary pattern printing. Therefore, the method of setting the sub-resolution auxiliary pattern on the outside of the main pattern still needs improvement. Summary of the Invention

[0004] One of the objectives of this invention is to provide a method for setting sub-resolution auxiliary graphics, which can set sub-resolution auxiliary graphics with high precision on the outside of the main graphic, thereby improving the exposure effect of the main graphic and increasing the exposure process window.

[0005] To achieve the above objectives, the present invention provides a method for setting sub-resolution auxiliary graphics. The method includes: inputting a main graphic; performing boundary optimization on the main graphic to obtain an optimized graphic; defining a region outside the optimized graphic that can be used to set the sub-resolution auxiliary graphics as a first region, wherein the boundary of the first region has a greater than zero gap with the boundary of the optimized graphic, and the first region is divided into multiple pixels, each pixel having a written state and a non-written state, and the initial state of all pixels in the first region is set to the non-written state; determining the key boundary of the optimized graphic; setting an initial sub-resolution auxiliary graphic in the first region for the key boundary; calculating the evaluation value corresponding to each of the multiple pixel states of the initial sub-resolution auxiliary graphic using an OPC model; selecting the graphic corresponding to the pixel state with the smallest evaluation value as the preferred sub-resolution auxiliary graphic; and modifying the state of all pixels corresponding to the preferred sub-resolution auxiliary graphic to the written state to determine the preferred sub-resolution auxiliary graphic.

[0006] Optionally, the method for optimizing the boundary of the main graphic to obtain an optimized graphic includes: shrinking or expanding the boundary at the corner of the main graphic to form an optimized graphic.

[0007] Optionally, the method for setting an initial sub-resolution auxiliary graphic in the first region for the key boundary includes: determining pixels in the first region whose distance from the key boundary is within a set range as pixels of the initial sub-resolution auxiliary graphic.

[0008] Optionally, the method for determining the critical boundaries of the optimized graphic and setting initial sub-resolution auxiliary graphics in the first region for the critical boundaries includes: determining the primary critical boundaries of the optimized graphic and setting primary initial sub-resolution auxiliary graphics corresponding to the primary critical boundaries in the first region; determining the secondary critical boundaries of the optimized graphic and setting secondary initial sub-resolution auxiliary graphics corresponding to the secondary critical boundaries in the first region; removing the regions where the primary and secondary initial sub-resolution auxiliary graphics are set, and setting tertiary initial sub-resolution auxiliary graphics in the remaining regions of the first region.

[0009] Optionally, the method for determining the primary critical boundary of the optimized graphic includes: using the boundary at the corner of the optimized graphic as the primary critical boundary.

[0010] Optionally, the method of calculating the evaluation value corresponding to each of the multiple pixel states of the initial sub-resolution auxiliary graphic using the OPC model, and selecting the graphic corresponding to the pixel state with the smallest evaluation value as the preferred sub-resolution auxiliary graphic includes: using the OPC model to combine the multiple pixels corresponding to each initial sub-resolution auxiliary graphic to obtain multiple pixel combinations, where each pixel combination corresponds to a pixel state of the initial sub-resolution auxiliary graphic; using the EPE evaluation function to calculate the evaluation value corresponding to each pixel combination, and confirming the graphic corresponding to the pixel combination with the smallest evaluation value as the preferred sub-resolution auxiliary graphic, wherein when calculating the evaluation value of a pixel combination, the state of the pixels within the pixel combination is defaulted to the written state, and the state of the pixels outside the pixel combination in the same initial sub-resolution auxiliary graphic is defaulted to the unwritten state.

[0011] Optionally, a pixel has two pixel states, an initial sub-resolution auxiliary graphic has n pixels, where n is a positive integer greater than 1, and an initial sub-resolution auxiliary graphic has 2 n A combination of pixels and having 2 n Individual pixel states.

[0012] Optionally, after modifying the state of all pixels corresponding to the preferred sub-resolution auxiliary graphic to the write state to determine the preferred sub-resolution auxiliary graphic, the method further includes: using the OPC model to perform overall detection on all the preferred sub-resolution auxiliary graphics, correcting the preferred sub-resolution auxiliary graphics that do not meet the set rules, and obtaining the final sub-resolution auxiliary graphic corresponding to each preferred sub-resolution auxiliary graphic; and outputting the optimized graphic of the main graphic and the final sub-resolution auxiliary graphic.

[0013] Optionally, both the final sub-resolution auxiliary graphic and the optimized graphic of the main graphic are set on the mask. The final sub-resolution auxiliary graphic is strip-shaped, and its width is smaller than the minimum graphic width that the mask can expose but larger than the minimum graphic width that can be produced on the mask.

[0014] Optionally, one pixel is a small square grid, and the width of the final sub-resolution auxiliary graphic is equal to the width of one pixel.

[0015] Optionally, when the setting value of the pixel is 0, it indicates that the pixel is in an unwritten state, and when the setting value of the pixel is 1, it indicates that the pixel is in a written state; or, when the setting value of the pixel is 1, it indicates that the pixel is in an unwritten state, and when the setting value of the pixel is 0, it indicates that the pixel is in a written state.

[0016] The sub-resolution auxiliary pattern setting method provided by this invention first optimizes the boundary of the main pattern to obtain an optimized pattern. Then, the area outside the optimized pattern that can be used to set the sub-resolution auxiliary pattern is determined as a first region. The boundary of the first region has a greater than zero gap with the boundary of the optimized pattern, and the first region is divided into multiple pixels. Each pixel has a written state and a non-written state. The initial state of all pixels in the first region is set to the non-written state. The key boundary of the optimized pattern is determined, and an initial sub-resolution auxiliary pattern is set in the first region for the key boundary. Then, the evaluation value corresponding to each of the multiple pixel states of the initial sub-resolution auxiliary pattern is calculated using an OPC model. The pattern corresponding to the pixel state with the smallest evaluation value is selected as the preferred sub-resolution auxiliary pattern. Then, the state of all pixels corresponding to the preferred sub-resolution auxiliary pattern is modified to the written state to determine the preferred sub-resolution auxiliary pattern. The unexpected technical effect of setting the sub-resolution auxiliary pattern in this way is that the sub-resolution auxiliary pattern can be set with high precision outside the main pattern, which helps to improve the exposure effect of the main pattern and increase the exposure process window. Moreover, the sub-resolution auxiliary pattern setting method of this application can also add pixelated sub-resolution auxiliary patterns in a limited space, and has a wide range of applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an existing sub-resolution auxiliary graphic.

[0018] Figure 2 This is a flowchart illustrating a method for setting sub-resolution auxiliary graphics according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the main graphic provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of an optimized main graphic provided for an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram illustrating the pixelation process of the outer region of the optimized graphic in one embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of setting up a first region in one embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram illustrating the setting of sub-resolution auxiliary graphics for the primary critical boundaries of the optimized graphics in this embodiment.

[0024] Figure 8 This is a schematic diagram illustrating the setting of sub-resolution auxiliary graphics for the secondary critical boundaries of the optimized graphics in this embodiment.

[0025] Figure 9 This is a schematic diagram showing the sub-resolution auxiliary graphics set in the blank area of ​​the first region in this embodiment. Detailed Implementation

[0026] In order to set sub-resolution auxiliary graphics with high precision on the outside of the main graphic, improve the exposure effect of the main graphic, and increase the exposure process window, the present invention provides a method for setting sub-resolution auxiliary graphics.

[0027] The method for setting sub-resolution auxiliary graphics proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the embodiments of this invention.

[0028] Figure 2 This is a flowchart illustrating a method for setting sub-resolution auxiliary graphics according to an embodiment of the present invention. Figure 2 As shown, the method for setting sub-resolution auxiliary graphics provided in this embodiment includes:

[0029] Step S1: Input the main graphic and perform boundary optimization on the main graphic to obtain the optimized graphic of the main graphic;

[0030] Step S2: The area outside the optimized graphic that can be used to set the sub-resolution auxiliary graphic is defined as the first region. The boundary of the first region has a distance greater than zero between it and the boundary of the optimized graphic. The first region is divided into multiple pixels, each of which has a written state and an unwritten state. The initial state of all pixels in the first region is set to the unwritten state.

[0031] Step S3: Determine the key boundaries of the optimized graphic, and set an initial sub-resolution auxiliary graphic in the first region for the key boundaries;

[0032] Step S4: Calculate the evaluation values ​​corresponding to multiple pixel states of the initial sub-resolution auxiliary graphic using the OPC model, and select the graphic corresponding to the pixel state with the smallest evaluation value as the preferred sub-resolution auxiliary graphic.

[0033] Step S5: Modify the state of all pixels corresponding to the preferred sub-resolution auxiliary graphic to the write state to determine the preferred sub-resolution auxiliary graphic.

[0034] It should be understood that, although Figure 2The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0035] Figure 3 This is a schematic diagram of a main graphic provided according to an embodiment of the present invention. (See reference) Figure 3 As shown, in step S1, inputting the main graphic 100 may include defining the size, position, and boundaries of the main graphic 100, but is not limited to this.

[0036] In step S1, the method for optimizing the boundary of the main graphic to obtain an optimized graphic may include: shrinking or expanding the boundary at the corner of the main graphic to form an optimized graphic, but is not limited to this. In other embodiments, when optimizing the boundary of the main graphic, other boundaries of the main graphic that need to be optimized may also be optimized.

[0037] Figure 4 This is a schematic diagram of an optimized main graphic provided in an embodiment of the present invention. (See reference) Figure 3 and Figure 4 As shown, when optimizing the boundary of the main graphic 100, some corners of the main graphic 100 can be optimized to obtain an optimized graphic 101, but this is not the only possibility. In other embodiments, all corners of the main graphic 100 can also be optimized. (See reference...) Figure 3 and Figure 4 As shown, for example, for a corner whose sharp corner points to the outside of the main graphic 100, the boundary at that corner can be expanded outward; for a corner whose sharp corner points to the inside of the main graphic 100, the boundary at that corner can be shrunk inward, but not limited to this.

[0038] Figure 5 This is a schematic diagram illustrating the pixelation process of the outer region of the optimized graphic in one embodiment of the present invention. Figure 6 This is a schematic diagram of setting up a first region in one embodiment of the present invention.

[0039] like Figure 6 As shown, in step S2, the area outside the optimized graphic 101 that can be used to set the sub-resolution auxiliary graphic is defined as the first region G1. The boundary of the first region G1 has a greater than zero distance between it and the boundary of the optimized graphic 101, and the first region G1 is divided into multiple pixels, for example... Figure 6 In the first region G1, each dashed grid represents a pixel. Each pixel has two states: a written state and an unwritten state. The initial state of all pixels in the first region G1 is set to the unwritten state.

[0040] Specifically, such as Figure 5 As shown, at least a portion of the blank area outside the optimized graphic 101 can be set as the initial setting area S1 of the auxiliary graphic. The initial setting area S1 of the auxiliary graphic can be pixelated, that is, the initial setting area S1 of the auxiliary graphic can be divided into multiple pixels; as shown... Figure 6 As shown, the region in the initial setting area S1 of the auxiliary graphics that has a set distance from the boundary of the optimized graphics 101 is set as the first region G1 for setting the sub-resolution auxiliary graphics, and the set distance is greater than zero.

[0041] It should be noted that when setting the initial setting area S1 of the auxiliary graphics, the initial setting area S1 of the auxiliary graphics should be defined as large as possible. In this embodiment, the optimized graphics 101 of the main graphics and the final sub-resolution auxiliary graphics are set on the mask, as shown in the reference. Figure 6 As shown, a pixel is a small square grid. The width of a pixel is less than the minimum pattern width that the mask can expose but greater than the minimum pattern width that can be made on the mask. This can prevent sub-resolution auxiliary patterns from being printed onto the photoresist layer or the product, and can ensure that sub-resolution auxiliary patterns can be made onto the mask.

[0042] In this embodiment, a pixel setting value of 0 indicates that the pixel is in an unwritten state, and a pixel setting value of 1 indicates that the pixel is in a written state. In other embodiments, a pixel setting value of 1 can indicate that the pixel is in an unwritten state, and a pixel setting value of 0 can indicate that the pixel is in a written state.

[0043] Execute step S3 to determine the key boundary of the optimized graphic 101, and set an initial sub-resolution auxiliary graphic in the first region G1 for the key boundary of the optimized graphic 101.

[0044] For example, pixels within the first region G1 whose distance from the key boundary is within a set range can be determined as pixels of the initial sub-resolution auxiliary graphic. For example, the initial sub-resolution auxiliary graphic can be a pixel group composed of multiple pixels, and the initial sub-resolution auxiliary graphic can be a rectangle or other shapes. It should be noted that, in this application, "multiple" can refer to two or more.

[0045] In this embodiment, multiple initial sub-resolution auxiliary graphics can be set in the first region G1, and the multiple initial sub-resolution auxiliary graphics can also be distinguished into different levels.

[0046] Figure 7 This is a schematic diagram illustrating the setting of sub-resolution auxiliary graphics for the primary critical boundaries of the optimized graphics in this embodiment. Figure 8 This is a schematic diagram illustrating the setting of sub-resolution auxiliary graphics for the secondary critical boundaries of the optimized graphics in this embodiment. Figure 9 This is a schematic diagram illustrating the setting of sub-resolution auxiliary graphics in the blank area of ​​the first region in this embodiment. Figure 7 , Figure 8 and Figure 9 The images shown are all preferred sub-resolution auxiliary graphics.

[0047] For example, determining the key boundaries of the optimized graphic 101, and setting an initial sub-resolution auxiliary graphic for the key boundaries within a first region G1, may include: referencing Figure 7 As shown, the primary critical boundary P1 of the optimized graphic 101 is determined, and a primary initial sub-resolution auxiliary graphic corresponding to the primary critical boundary P1 is set within the first region G1; (Refer to...) Figure 8 As shown, the secondary critical boundary P2 of the optimized graphic 101 is determined, and a secondary initial sub-resolution auxiliary graphic corresponding to the secondary critical boundary P2 is set within the first region G1; (Refer to...) Figure 9 As shown, except for the areas where the first-level initial sub-resolution auxiliary graphics and the second-level initial sub-resolution auxiliary graphics are set, the remaining areas within the first area are set with the third-level initial sub-resolution auxiliary graphics.

[0048] refer to Figure 7 As shown, the boundary at the corner of optimized graph 101 can be used as the first-level critical boundary P1; as Figure 8 As shown, the boundary connected to the corner boundary can be used as a secondary critical boundary P2, but it is not limited to this.

[0049] In step S4, the evaluation values ​​corresponding to multiple pixel states of the initial sub-resolution auxiliary graphic are calculated using the OPC model. The graphic corresponding to the pixel state with the smallest evaluation value is selected as the preferred sub-resolution auxiliary graphic. When multiple initial sub-resolution auxiliary graphics are set in the first region G1, the evaluation values ​​corresponding to multiple pixel states of each initial sub-resolution auxiliary graphic can be calculated using the OPC model. The graphic corresponding to the pixel state with the smallest evaluation value is selected as the preferred sub-resolution auxiliary graphic of that initial sub-resolution auxiliary graphic.

[0050] Specifically, in step S4, the OPC (Optical Proximity Correction) model is used to combine multiple pixels corresponding to each initial sub-resolution auxiliary graphic to obtain multiple pixel combinations. Each pixel combination corresponds to a pixel state of the initial sub-resolution auxiliary graphic. The edge placement error (EPE) evaluation function is used to calculate the evaluation value corresponding to each pixel combination. The graphic corresponding to the pixel combination with the smallest evaluation value is confirmed as the preferred sub-resolution auxiliary graphic. When calculating the evaluation value of a pixel combination, the state of the pixels within the pixel combination is defaulted to the written state (e.g., 1), and the state of the pixels outside the pixel combination in the same initial sub-resolution auxiliary graphic is defaulted to the unwritten state (e.g., 0).

[0051] The EPE evaluation function can be a function in the OPC model, but is not limited to it.

[0052] For example, an initial sub-resolution auxiliary graphic has n pixels, where n is a positive integer greater than 1. Each pixel has two states: written and unwritten. Thus, the n pixels of an initial sub-resolution auxiliary graphic can have 2 n A combination of pixels, that is, having 2 n Each pixel state is then calculated separately. n The evaluation value corresponding to each pixel state is obtained as 2. n Each evaluation value is used to select the pixel state with the smallest evaluation value as the preferred sub-resolution auxiliary image.

[0053] For example, after setting the first-level initial sub-resolution auxiliary graphics, the second-level initial sub-resolution auxiliary graphics, and the third-level initial sub-resolution auxiliary graphics, step S4 is performed, referring to... Figure 7 As shown, the first-level preferred sub-resolution auxiliary graphic F1 corresponding to the first-level initial sub-resolution auxiliary graphic is obtained, with reference to... Figure 8 As shown, the second-level preferred sub-resolution auxiliary pattern F2 corresponding to the second-level initial sub-resolution auxiliary pattern is obtained, and, with reference to Figure 9 As shown, the optimal sub-resolution auxiliary graphic F3 corresponding to the initial sub-resolution auxiliary graphic of the third level is obtained.

[0054] Execute step S5, modify the state of all the pixels corresponding to the preferred sub-resolution auxiliary graphic to the write state to determine the preferred sub-resolution auxiliary graphic, for example, modify the state of all the pixels corresponding to the preferred sub-resolution auxiliary graphic to 1.

[0055] Next, step S6 is executed, in which the OPC model is used to perform an overall detection on all the preferred sub-resolution auxiliary graphics, and the preferred sub-resolution auxiliary graphics that do not meet the set rules are corrected to obtain the final sub-resolution auxiliary graphics corresponding to each preferred sub-resolution auxiliary graphics.

[0056] The setting rules can be set as needed. Correcting the preferred sub-resolution auxiliary graphic that does not meet the setting rules may include moving the preferred sub-resolution auxiliary graphic and removing some pixels. For the corresponding preferred sub-resolution auxiliary graphic and final sub-resolution auxiliary graphic, the state of all pixels corresponding to the final sub-resolution auxiliary graphic can be set to the write state (i.e., all set to 1), and the state of pixels in the preferred sub-resolution auxiliary graphic that do not overlap with the final sub-resolution auxiliary graphic can be modified to the non-write state (i.e., modified to 0), that is, the pixel is deleted.

[0057] Execute step S7 to output the optimized graphic 101 of the main graphic and the final sub-resolution auxiliary graphic.

[0058] Specifically, the graphic composed of pixels whose final pixel state is 1 is identified as the final sub-resolution auxiliary graphic, and all pixels whose final pixel state is 1 can form one or more final sub-resolution auxiliary graphics.

[0059] The output of the optimized graphic 101 of the main graphic and the final sub-resolution auxiliary graphic may include the size, position, and boundary of the output optimized graphic 101 and the final sub-resolution auxiliary graphic.

[0060] It should be noted that both the final sub-resolution auxiliary graphic and the optimized graphic of the main graphic are set on the mask. The final sub-resolution auxiliary graphic can be strip-shaped. The width of the final sub-resolution auxiliary graphic is smaller than the minimum graphic width that the mask can expose but larger than the minimum graphic width that can be produced on the mask. This can prevent the final sub-resolution auxiliary graphic from being printed on the photoresist layer or the product.

[0061] refer to Figures 7 to 9 As shown, the preferred sub-resolution auxiliary graphic and its corresponding final sub-resolution auxiliary graphic are both straight or curved strips. The preferred sub-resolution auxiliary graphic and its corresponding final sub-resolution auxiliary graphic can be formed by arranging a single row of pixels. The width of a final sub-resolution auxiliary graphic is equal to the width of a pixel. The width of a pixel is less than the minimum graphic width that the mask can expose and greater than the minimum graphic width that can be made on the mask.

[0062] In the sub-resolution auxiliary graphic setting method provided by the present invention, firstly, the main graphic 100 is optimized by boundary to obtain an optimized graphic 101 of the main graphic. Then, the area outside the optimized graphic 101 that can be used to set the sub-resolution auxiliary graphic is determined as a first region G1. The boundary of the first region G1 and the boundary of the optimized graphic 101 have a distance greater than zero, and the first region G1 is divided into multiple pixels. Each pixel has a written state and a non-written state. The initial state of all pixels in the first region is set to the non-written state. The key boundary of the optimized graphic 101 is determined, and the initial sub-resolution auxiliary graphic is set in the first region G1 for the key boundary. Then, the evaluation value corresponding to each of the multiple pixel states of the initial sub-resolution auxiliary graphic is calculated using the OPC model. The graphic corresponding to the pixel state with the smallest evaluation value is selected as the preferred sub-resolution auxiliary graphic. Then, the state of all pixels corresponding to the preferred sub-resolution auxiliary graphic is modified to the written state to determine the preferred sub-resolution auxiliary graphic. The unexpected technical effect of setting the sub-resolution auxiliary graphic in this way is that the sub-resolution auxiliary graphic can be set with high precision on the outside of the main graphic 100, which helps to improve the exposure effect of the main graphic, increase the exposure process window, and help to improve defects such as line stripping and top loss caused by poor exposure effect. Furthermore, the sub-resolution auxiliary graphic setting method of this application can also add pixelated sub-resolution auxiliary graphics in a limited space, which has a wide range of applications.

[0063] Furthermore, each pixel is a small square grid, and the width of the final sub-resolution auxiliary graphic is equal to the width of one pixel. The width of the final sub-resolution auxiliary graphic is less than the minimum graphic width that the mask can expose but greater than the minimum graphic width that can be produced on the mask. The unexpected technical effect is that it can effectively prevent the sub-resolution auxiliary graphic from being exposed on the product, which helps to improve the product yield.

[0064] The present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed, implements the above-described method for setting sub-resolution auxiliary graphics.

[0065] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for setting sub-resolution auxiliary graphics, characterized in that, include: Input the main graphic, and perform boundary optimization on the main graphic to obtain the optimized graphic of the main graphic; The area outside the optimized graphic that can be used to set the sub-resolution auxiliary graphic is defined as the first region. The boundary of the first region has a distance greater than zero between it and the boundary of the optimized graphic. The first region is divided into multiple pixels, each of which has a written state and an unwritten state. The initial state of all pixels in the first region is set to the unwritten state. Determine the key boundaries of the optimized graphic, and set an initial sub-resolution auxiliary graphic in the first region for the key boundaries; The evaluation values ​​corresponding to multiple pixel states of the initial sub-resolution auxiliary graphic are calculated using the OPC model. The graphic corresponding to the pixel state with the smallest evaluation value is selected as the preferred sub-resolution auxiliary graphic. The OPC model is used to combine multiple pixels corresponding to the initial sub-resolution auxiliary graphic to obtain multiple pixel combinations, each pixel combination corresponding to one pixel state of the initial sub-resolution auxiliary graphic. The edge placement error evaluation function of the OPC model is used to calculate the evaluation value corresponding to each pixel combination. The evaluation value is the edge placement error value. The graphic corresponding to the pixel combination with the smallest evaluation value is confirmed as the preferred sub-resolution auxiliary graphic. When calculating the evaluation value of a pixel combination, the state of pixels within the pixel combination is defaulted to a written state, while the state of pixels outside the pixel combination in the same initial sub-resolution auxiliary graphic is defaulted to an unwritten state. The state of all pixels corresponding to the preferred sub-resolution auxiliary graphic is modified to a write state to determine the preferred sub-resolution auxiliary graphic.

2. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, The method for optimizing the boundary of the main graphic to obtain an optimized graphic includes: shrinking or expanding the boundary at the corner of the main graphic to form an optimized graphic.

3. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, The method for setting an initial sub-resolution auxiliary graphic in the first region for the critical boundary includes: determining pixels in the first region whose distance from the critical boundary is within a set range as pixels of the initial sub-resolution auxiliary graphic.

4. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, The method for determining the critical boundaries of the optimized graphic and setting initial sub-resolution auxiliary graphics in the first region for the critical boundaries includes: determining the primary critical boundaries of the optimized graphic and setting primary initial sub-resolution auxiliary graphics corresponding to the primary critical boundaries in the first region; determining the secondary critical boundaries of the optimized graphic and setting secondary initial sub-resolution auxiliary graphics corresponding to the secondary critical boundaries in the first region; removing the regions where the primary and secondary initial sub-resolution auxiliary graphics are set, and setting tertiary initial sub-resolution auxiliary graphics in the remaining regions of the first region.

5. The method for setting sub-resolution auxiliary graphics as described in claim 4, characterized in that, The method for determining the primary critical boundary of the optimized graphic includes: using the boundary at the corner of the optimized graphic as the primary critical boundary.

6. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, A pixel has two pixel states, an initial sub-resolution auxiliary graphic has n pixels, where n is a positive integer greater than 1, and an initial sub-resolution auxiliary graphic has 2 n A combination of pixels and having 2 n Individual pixel states.

7. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, After modifying the state of all pixels corresponding to the preferred sub-resolution auxiliary pattern to a write state to determine the preferred sub-resolution auxiliary pattern, the method further includes: The OPC model is used to perform an overall detection on all the preferred sub-resolution auxiliary graphics, and the preferred sub-resolution auxiliary graphics that do not meet the set rules are corrected to obtain the final sub-resolution auxiliary graphics corresponding to each preferred sub-resolution auxiliary graphic; and Output the optimized graphics of the main graphic and the final sub-resolution auxiliary graphics.

8. The method for setting sub-resolution auxiliary graphics as described in claim 7, characterized in that, Both the final sub-resolution auxiliary graphic and the optimized graphic of the main graphic are set on the mask. The final sub-resolution auxiliary graphic is strip-shaped, and its width is smaller than the minimum graphic width that the mask can expose but larger than the minimum graphic width that can be made on the mask.

9. The method for setting sub-resolution auxiliary graphics as described in claim 8, characterized in that, Each pixel is a small square grid, and the width of the final sub-resolution auxiliary graphic is equal to the width of one pixel.

10. The method for setting sub-resolution auxiliary graphics as described in claim 1, characterized in that, When the pixel is set to 0, it indicates that the pixel is in an unwritten state; when the pixel is set to 1, it indicates that the pixel is in a written state. Alternatively, when the pixel is set to 1, it indicates that the pixel is in an unwritten state; when the pixel is set to 0, it indicates that the pixel is in a written state.

Images