Sub-pixel image processing method and system based on mask gridding area

Abstract

The invention discloses a sub-pixel processing method and system based on a mask gridding area, and the method comprises the steps: S1, building a virtual grid with specified length and width based on a mask design file, initializing the gray values of all grid units in the virtual grid to 0, and recording the area of each grid unit as Sg; s2, reading all graphs in a mask design file as corresponding polygons and presenting the polygons at corresponding positions in the virtual grid; s3, determining a grid penetrated by the polygon boundary and a grid completely located in the polygon boundary, and respectively recording the grids as W1 and W2; s4, the area Sn of the part, located in the polygon boundary, of the W1 is calculated, the gray value H of the W1 is set to be the ratio of Sn to Sg, and H is larger than 0 and smaller than 1; the gray value of W2 is set to be 1 through internal filling; and S5, storing the calculated gray value H as a sub-pixel image. According to the invention, the implementation efficiency of the sub-pixel technology can be improved.

Description

Technical Field

[0001] The invention relates to photolithography mask manufacturing, in particular to a sub-pixel processing method and system based on mask gridding area. Background Art

[0002] Laser direct writing lithography machine is one of the key equipment for photolithography mask manufacturing. Sub-pixel technology is one of the key technologies to improve the resolution and fidelity of laser direct writing lithography patterns. By adjusting the intensity of the laser beam, the exposure position of the edge of the mask pattern can be precisely controlled to achieve more precise edge position control, reduce edge placement errors, and improve the critical dimensions and pattern fidelity of the lithography pattern, so that micron or even nanometer-level microstructures can be manufactured.

[0003] Sub-pixel technology achieves higher resolution and accuracy by further subdividing each pixel and modulating the intensity of the laser scanning lithography machine's beam. As the lithography node shrinks, the mask graphics become more complex, and the number of design graphics that need to be processed by sub-pixel continues to increase, resulting in the time consumption of sub-pixel technology increasing. In order to achieve higher production efficiency, the time consumption for sub-pixel processing needs to be as short as possible. Therefore, how to improve the implementation efficiency of sub-pixel technology while ensuring accuracy has become a crucial issue. Summary of the invention

[0004] In view of this, the first object of the present invention is to provide a sub-pixel image processing method based on a mask grid area, which can improve the implementation efficiency of the sub-pixel technology.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A sub-pixel image processing method based on a mask gridding area, comprising:

[0007] S1. Create a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g .

[0008] S2, reading all the graphics in the mask design file as corresponding polygons and presenting them at corresponding positions in the virtual grid;

[0009] S3, determine the meshes that are passed through the polygon boundary and the meshes that are completely inside the polygon boundary, and record them as W1 and W2 respectively;

[0010] S4. Calculate the area S of the part of W1 within the polygon boundary n , set the gray value H of W1 to S n With S gThe ratio of , where 0<H<1; and the gray value of W2 is set to 1 by internal filling:

[0011] S5. Save the calculated grayscale value H as an array, and store it as a sub-pixel image according to a preset array conversion format.

[0012] Preferably, in step S3, the Bresenham algorithm is used to determine the meshes passed through by the polygonal boundary.

[0013] Preferably, in step S4, a Boolean operation is used to determine the area of ​​W1 within the polygon boundary, and S is calculated by the following formula: n :

[0014]

[0015] Where (x i ,y i ) are polygon coordinates, (x n+1 ,y n+1 ) and (x 1 ,y 1 )same.

[0016] Preferably, in step S4, a scan line algorithm is used to fill the mesh completely inside the polygon boundary.

[0017] The second object of the present invention is to provide a sub-pixel image processing method based on a mask grid area, which can improve the implementation efficiency of the sub-pixel technology.

[0018] In order to achieve the above object, the technical solution of the present invention is:

[0019] A sub-pixel image processing device based on a mask gridding area, comprising:

[0020] The first processing unit is configured to establish a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g ;

[0021] a second processing unit configured to read all the graphics in the mask design file as corresponding polygons and present them at corresponding positions in the virtual grid; a third processing unit configured to determine the grids passed by the polygon boundary and the grids completely inside the polygon boundary, which are respectively denoted as W1 and W2;

[0022] The fourth processing unit is configured to calculate the area of ​​the portion of W1 within the polygon boundary.

[0023] S n, set the gray value H of w1 to S n With S g , where 0<H<1; and setting the gray value of W2 to 1 by internal filling;

[0024] The fifth processing unit is configured to save the calculated grayscale value H as an array, and store it as a sub-pixel image according to a preset array conversion format.

[0025] The technical effects of the present invention are mainly reflected in the following aspects:

[0026] The present invention reads the coordinates of a graphic in a mask design file, judges the relative position of the grid in the graphic according to the grid size of the mask, determines the grid passed by the polygon boundary by the Bresenham algorithm, calculates the grayscale value of the boundary grid as the ratio of the area of ​​the intersection part to the area of ​​the grid, determines the grid inside the polygon by the scan line algorithm, sets the grayscale value of the grid inside the polygon to 1, and sets the grayscale values ​​of the remaining grids to 0, finally obtains the grayscale values ​​of all the grids and converts them into sub-pixel arrays, thereby obtaining an accurate mask grayscale image, achieving more accurate light intensity modulation, and having better implementation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of the method in the embodiment;

[0028] Figure 2 Schematic diagram of the positional relationship between polygons and grids in the embodiment (wherein A, B, C, and D are vertices of the figure, 1 is a grid W2 completely located inside the polygon; 2 is a grid W1 passed through by the polygon boundary; and 3 is a grid outside the polygon);

[0029] Figure 3 Schematic diagram of the intersection of a circular exposure pattern and a pixel grid in an embodiment (wherein 4 is a grid W2 completely located inside the circle; 5 is a grid W1 passed through by the circular boundary; 6 is a grid outside the circle);

[0030] Figure 4 and Figure 5 is a grayscale image in the embodiment;

[0031] Figure 6 It is a grayscale two-dimensional array data diagram in the embodiment. DETAILED DESCRIPTION

[0032] The specific implementation modes of the present invention are further described below in conjunction with the accompanying drawings to make the technical solutions of the present invention easier to understand and grasp.

[0033] Embodiment 1

[0034] like Figure 1As shown, this embodiment provides a sub-pixel image processing method based on a mask grid area, comprising:

[0035] S1. Create a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g .

[0036] S2. Read all graphics in the mask design file as corresponding polygons and present them at corresponding positions in the virtual grid.

[0037] Specifically, the mask design file is converted into polygons by calling the algorithm interface of the klayout open source library to identify the graphics. The klayout open source library is a common open source library on the market, and its use is well known to those skilled in the art, so it will not be repeated in this embodiment.

[0038] S3. Determine the meshes that are passed through the polygon boundary and the meshes that are completely inside the polygon boundary, which are denoted as W1 and W2 respectively. Specifically, use the Bresenham algorithm to determine the meshes that are passed through the polygon boundary, so that the meshes that are completely inside the polygon are determined.

[0039] In this step, the core idea of ​​the Bresenham line algorithm is to use incremental calculation to avoid floating-point operations, thereby improving the calculation efficiency. This algorithm can be used to find the grid edge through which the straight line passes, and is commonly used in graphics and grid path planning, so the specific principle will not be described in detail in this embodiment.

[0040] S4. Calculate the area S of the part of W1 within the polygon boundary n , set the gray value H of W1 to S n With S g The ratio of , where 0<H<1;

[0041] And, the gray value of W2 is set to 1 by internal filling; in this step, the scan line algorithm is specifically used to fill the grid inside the polygon.

[0042] In this step, the core idea of ​​using the scan line algorithm to fill is to divide the grids in a row into three categories, corresponding to three states, namely outside the polygon, boundary, and inside the polygon. First, at the beginning of each row, the first pixel is judged to determine the initial state, and then the grid is traversed backward until a boundary point appears, the state is switched to the boundary point, and the traversal is continued. When a point that is not marked as a boundary point appears, the pixel is judged to determine the next state. Repeating this process continuously, all grids inside the polygon can be found and the filling inside the polygon is completed.

[0043] In step S4, the area of ​​W1 within the polygon boundary is determined using Boolean operations, and S is calculated using the following formula: n :

[0044]

[0045] Where (x i ,y i ) are polygon coordinates, (x n+1 ,y n+1 ) and (x 1 ,y 1 ) is the same, since polygons or circles are closed loops, so (x n+1 ,y n+1 ) and (x 1 ,y 1 ) is the same point.

[0046] S5, save the calculated gray value H as an array, and store it as a sub-pixel image according to a preset array conversion format. In this way, the sub-pixel arrays of all grids and the accurate gray image of the mask can be obtained, as shown in the following figure: Figure 4 and Figure 5 At the same time, the data of the sub-pixel array can also be obtained, as shown in Figure 6 After the calculation is completed, the intensity of the laser scanning lithography machine beam can be precisely modulated through the generated grayscale data, thereby achieving more accurate lithography.

[0047] It is worth noting that in step S1, the recognized shape can be a general polygon, as shown in FIG. Figure 2 As shown, it may also be a circle. Figure 3 shown in Figure 3 In the example, the shoelace algorithm can be used to calculate the area of ​​the area enclosed by the straight line segment and the sector area of ​​the arc part. By combining several parts, the accurate S n .

[0048] Embodiment 2

[0049] This embodiment provides a sub-pixel image processing device based on a gridded area of ​​a mask, a first processing unit, a second processing unit, a third processing unit, a fourth processing unit and a fifth processing unit.

[0050] The first processing unit is configured to establish a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g ;

[0051] The second processing unit is configured to read all the graphics in the mask design file into corresponding polygons and present them at corresponding positions in the virtual grid;

[0052] A third processing unit is configured to determine the meshes that are passed through the polygon boundary and the meshes that are completely inside the polygon boundary, which are denoted as W1 and W2 respectively;

[0053] The fourth processing unit is configured to calculate the area S of the portion of W1 within the polygon boundary. n , set the gray value H of W1 to S n With S g , where 0<H<1; and setting the gray value of W2 to 1 by internal filling;

[0054] The fifth processing unit is configured to save the calculated grayscale value H as an array, and store it as a sub-pixel image according to a preset array conversion format.

[0055] Embodiment 3

[0056] This embodiment provides a lithography machine control system, the system comprising:

[0057] one or more memories for storing instructions; and

[0058] One or more processors are used to call and run the instructions from the memory to execute the method described in embodiment one.

[0059] Embodiment 4:

[0060] This embodiment provides a computer-readable storage medium, wherein the computer-readable storage medium includes:

[0061] Program, when the program is executed by a processor, the method described in embodiment 1 is executed.

[0062] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A sub-pixel image processing method based on a mask grid area, characterized in that: include: S1. Create a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g . S2, reading all the graphics in the mask design file as corresponding polygons and presenting them at corresponding positions in the virtual grid; S3, determine the meshes that are passed through the polygon boundary and the meshes that are completely inside the polygon boundary, and record them as W1 and W2 respectively; S4. Calculate the area S of the part of W1 within the polygon boundary h , set the gray value H of W1 to S n With S g , where 0<H<1; and setting the gray value of W2 to 1 by internal filling; S5. Save the calculated grayscale value H as an array, and store it as a sub-pixel image according to a preset array conversion format.

2. A sub-pixel image processing method based on mask gridding area as claimed in claim 1, characterized in that: In step S3, the Bresenham line algorithm is used to determine the meshes that are crossed by the polygon boundary.

3. A sub-pixel image processing method based on mask gridding area as claimed in claim 2, characterized in that In step S4, the intersection operation of Boolean operation is used to determine the area of ​​W1 within the polygon boundary, and S is calculated by the following formula: n : Where (x i ,y i ) are polygon coordinates, (x n+1 ,y n+1 ) is the same as (x1, y1).

4. The sub-pixel image processing method based on mask gridding area according to claim 1, characterized in that: In step S4, a scan line algorithm is used to fill the mesh completely inside the polygon boundary.

5. A sub-pixel image processing device based on a mask grid area, characterized in that: include: The first processing unit is configured to establish a virtual grid of specified length and width based on the mask design file, and initialize the grayscale values ​​of all grid cells in the virtual grid to 0, and the area of ​​each grid cell is recorded as S g ; A second processing unit, configured to read all graphics in the mask design file as corresponding polygons and present them at corresponding positions in the virtual grid; The third processing unit determines the meshes that are crossed by the polygon boundary and the meshes that are completely inside the polygon boundary, which are recorded as W1 and W2 respectively; The fourth processing unit calculates the area S of the part of W1 within the polygon boundary n , set the gray value H of W1 to S n With S g , where 0<H<1; and setting the gray value of W2 to 1 by internal filling; The fifth processing unit is configured to save the calculated grayscale value H as an array, and store it as a sub-pixel image according to a preset array conversion format.

6. A photolithography machine control system, characterized in that: The system comprises: one or more memories for storing instructions; and One or more processors, configured to call and execute the instructions from the memory to perform the method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The computer readable storage medium comprises: The program, when the program is executed by a processor, the method according to any one of claims 1 to 4 is executed.

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