Method for hierarchical recognition of patterns

Abstract

The application provides a method for recognizing a pattern by layers, and provides a design file of a photolithography mask plate. The design file represents polygons in a layered form. Each layer of the polygons is uniformly divided into a plurality of strip areas. A strip area located in the interior of the polygon is assigned a first set value, and a strip area located in the exterior of the polygon is assigned a second set value. The first and second set values are different. Each layer of the polygons is assigned a specific coefficient. A numerical sequence representing each strip area is obtained by multiplying the assigned value of the strip area in each layer of the polygon by the corresponding coefficient and then superimposing. The pattern is recognized according to the numerical sequence of all the strip areas. The pattern to be recognized is superimposed by layers, and the value of the superimposed area is searched, so that the pattern is quickly recognized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, in particular to a method for identifying patterns by levels. BACKGROUND

[0002] In the process of designing mask plate, it is necessary to check whether the patterns are correctly placed. As shown in the figure, ROTATION pattern is used to test the rotation error between mask plates. The ROTATION spliced between two shots is a complete pattern. Therefore, if the pattern is missing, it will cause the mask plate to be reset, the silicon wafer to be discarded, and other problems. Figure 1

[0003] The detection of the prior art pattern is based on logical judgment, that is, whether the pattern coordinate position is correct. However, this method is also prone to missing.

[0004] The prior art method for identifying patterns needs to compare the patterns geometrically to detect whether the patterns are correctly placed, which is very slow. Especially for the patterns after OPC (Optical Proximity Correction), the data volume is very large, which causes a large waste of computing resources.

[0005] As shown in the figure, at different positions of the scribing groove, A, B and C are only A is correct. Figure 2

[0006] In order to solve the above problems, a new method for identifying patterns by levels is needed. SUMMARY

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a method for identifying patterns by levels, which solves the problem that the prior art method for identifying patterns needs to compare the patterns geometrically to detect whether the patterns are correctly placed, which is very slow. Especially for the patterns after OPC (Optical Proximity Correction), the data volume is very large, which causes a large waste of computing resources.

[0008] To achieve the above-mentioned purposes and other related purposes, the present application provides a method for identifying patterns by levels, comprising:

[0009] Step one, providing a design file of a photomask, the design file representing polygons in a layered form;

[0010] Step two, uniformly dividing each layer of the polygons into a plurality of strip-shaped regions, assigning a first set value to the strip-shaped regions located inside the polygons, and assigning a second set value to the strip-shaped regions located outside the polygons, the first and second set values being different;

[0011] Step three, assigning a specific coefficient to each layer of the polygons; ​​

[0012] Step four, characterizing the numerical sequence of each of the strip regions: multiplying the value of the strip region in each layer of the polygon by the corresponding coefficient, and superimposing;

[0013] Step five, identifying the pattern according to the numerical sequence of all the strip regions.

[0014] Preferably, the design file of the mask in step one is in GDSII format.

[0015] Preferably, the topography of the strip regions in each layer of the polygon in step two is consistent.

[0016] Preferably, the first set value in step two is 1.

[0017] Preferably, the second set value in step two is 0.

[0018] As described above, the method for identifying patterns by hierarchy according to the present application has the following beneficial effects:

[0019] The present application superimposes the patterns to be identified by hierarchy, and retrieves the region value after superimposition, thereby realizing fast identification of patterns. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic diagram of a rotating pattern showing the prior art;

[0021] Figure 2 A schematic diagram of geometric comparison of patterns showing the prior art;

[0022] Figure 3 A schematic diagram of the method for identifying patterns by hierarchy according to the present application;

[0023] Figure 4 A schematic diagram of assigning values to strip regions according to the present application;

[0024] Figure 5 A schematic diagram of assigning specific coefficients to each layer of polygon according to the present application;

[0025] Figure 6 A schematic diagram of characterizing the numerical sequence of strip regions according to the present application;

[0026] Figure 7 A schematic diagram of comparison of numerical sequences of two patterns according to the present application. DETAILED DESCRIPTION

[0027] Following, the embodiments of the present application will be described in detail by specific examples. Other advantages and effects of the present application can be easily understood by those skilled in the art from the description. The present application can also be implemented or applied by other different embodiments, and the details in the description can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0028] Referring to Figure 3 The present application provides a method for recognizing a pattern by layers, comprising:

[0029] Step one, providing a design file of a photolithography mask, the design file representing polygons in a layered form;

[0030] In some embodiments, the design file of the mask in step one is in GDSII format. GDSII stream format, commonly known as GDSII, is a database file format. It is used for data conversion of integrated circuit layout and has become a de facto industry standard. GDSII is a binary file containing the geometric shapes of the planes in the integrated circuit layout, text or labels, and other related information and can be composed of a hierarchical structure. GDSII data can be used to reconstruct all or part of the layout information. It can be used to make photolithography masks.

[0031] Step two, uniformly dividing each layer of polygons into a plurality of strip regions, assigning a first set value to the strip regions located inside the polygons, assigning a second set value to the strip regions located outside the polygons, the first and second set values being different;

[0032] In some embodiments, the topography of the strip regions in each layer of polygons is consistent.

[0033] In some embodiments, the first set value in step two is 1.

[0034] In some embodiments, the second set value in step two is 0. In other embodiments, the first and second set values can also be adjusted, which is not specifically limited here.

[0035] Step three, assigning a specific coefficient to each layer of polygons;

[0036] Step four, representing the numerical sequence of each strip region: multiplying the assigned value of the strip region in each layer of polygons by the corresponding coefficient and superimposing;

[0037] Step five, recognizing the pattern according to the numerical sequence of all strip regions.

[0038] For example, referring to Figure 4For the two layers a and b, the polygon inside layer a is assigned 1, the polygon inside layer b is assigned 1, and the polygon outside is assigned 0.

[0039] Referring to Figure 5 For the two layers a and b, the polygon inside layer a is assigned 1, the polygon inside layer b is assigned 1, and the polygon outside is assigned 0.

[0040] Referring to Figure 6 The value of the strip region located at layers a and b is 1*0.5+1*0.5=1, the value of the strip region located at layer a is 1*0.5=0.5, and the value of the strip region outside the polygon is 0.

[0041] Referring to Figure 7 It can be clearly found that the value sequences of the two figures are inconsistent.

[0042] It should be noted that the diagrams provided in the embodiments only schematically illustrate the basic concepts of the present application, and only the components related to the present application are shown in the diagrams, rather than the number, shape and size of the components when actually implemented. The actual implementation of each component can be randomly changed in shape, number and proportion, and the layout of the components can be more complex.

[0043] In summary, the present application stacks the figures to be identified according to the hierarchy, and retrieves the region values after stacking, thereby achieving fast identification of the figures. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0044] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for identifying graphics by hierarchy, characterized in that, At least including: Step 1: Provide the design file for the photomask, wherein the design file represents polygons in a layered manner; Step 2: Divide each layer of the polygon into multiple strip regions evenly. Assign a first set value to the strip regions located inside the polygon and assign a second set value to the strip regions located outside the polygon. The first and second set values ​​are different. Step 3: Assign specific coefficients to each layer of polygons; Step 4: Characterize the numerical sequence of each strip region: multiply the assigned value of the strip region in each layer of the polygon by the corresponding coefficient, and then superimpose them; Step 5: Identify the pattern based on the numerical sequence of all the said strip regions.

2. The method for identifying graphics by hierarchy according to claim 1, characterized in that: The design file for the mask in step one is in GDSII format.

3. The method for identifying graphics by hierarchy according to claim 1, characterized in that: In step two, the shape of the strip-shaped regions in each layer of the polygon is consistent.

4. The method for identifying graphics by hierarchy according to claim 1, characterized in that: The first setting value in step two is 1.

5. The method for identifying graphics by hierarchy according to claim 4, characterized in that: The second setting value in step two is 0.

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