Pattern wafer pyramid dirt defect detection method, device and system and storage medium

Abstract

The invention relates to the technical field of wafer defect detection, in particular to a pattern wafer pyramid dirt defect detection method, device and system and a storage medium. According to the detection method, defect detection is carried out by comparing gray difference values of a reduced-size reference gray-scale map and an actual gray-scale map with different zooming multiples for multiple times. Therefore, the detection speed can be improved well, and the method can be suitable for detecting defects of different sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer defect detection, and in particular to a method, device, system and storage medium for detecting contamination defects of patterned wafer pyramids. Background Art

[0002] The pyramid of a patterned wafer is a structure of small display planes that appear on the surface after epitaxial growth. Its appearance defects such as surface dirt have always been a difficult problem in visual inspection. In the inspection based on the inspection template (such as the golden template), it is achieved by constructing an ideal inspection template of the area to be inspected and comparing the grayscale difference between the image of the actual inspection area and the inspection template; currently in this field, how to efficiently use the computing resources of the inspection equipment and accurately detect pyramid dirt for defects of different sizes is a hot topic of research. Summary of the invention

[0003] The present invention provides a method for detecting contamination defects of pattern wafer pyramids, which can overcome certain or some defects of the prior art.

[0004] The method for detecting contamination defects of pattern wafer pyramids according to the present invention comprises the following steps:

[0005] S1. Construct a detection template and obtain a reference grayscale image A of the area to be detected in the detection template, where A=I1[M,N]; I1[M,N] is the grayscale value of a pixel with M columns and N rows;

[0006] S2, obtaining the actual grayscale image B of the area to be detected, B = I2[M, N]; I2[M, N] is the grayscale value of the pixel point with M columns and N rows;

[0007] S3, simultaneously reducing the reference grayscale image A and the actual grayscale image B by n times, the reference grayscale image A after being reduced by n times is the grayscale image An, and the reference grayscale image B after being reduced by n times is the grayscale image Bn;

[0008] S4. Obtain the difference image ΔI between the grayscale image Bn and the grayscale image An n , ΔI n =A n -B n ; with ΔI n Pixels with grayscale values ​​greater than the set grayscale threshold are regarded as problem points, and the area of ​​all problem points connected in the actual grayscale image B is obtained as the defect area S;

[0009] When the defect area S is greater than the set area threshold, it is determined that there is a defect in the area to be inspected and the inspection is terminated;

[0010] When the defect area S is less than the set area threshold, n is assigned a value of n-1, and steps S3 and S4 are repeated to continue the detection until n=1;

[0011] S5. Output the detection results.

[0012] Preferably, the value of n is set so that the pixel size of the reference grayscale image A after being reduced n times is not less than 10.

[0013] Preferably, the grayscale threshold is set to 25.

[0014] Preferably, the area threshold is set to 15.

[0015] In addition, the present invention also provides a pattern wafer pyramid contamination defect detection device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of any one of the above-mentioned detection methods are implemented.

[0016] In addition, the present invention also provides a pattern wafer pyramid contamination defect detection system, which includes the above-mentioned pattern wafer pyramid contamination defect detection device.

[0017] In addition, the present invention also provides a computer-readable medium on which a computer program is stored, and when the computer program is executed, the steps of any one of the above-mentioned detection methods are implemented.

[0018] The beneficial effects of the present invention are as follows: due to the high density and large number of pattern wafer pyramids and the presence of groove structures, if there is dirt, the amount of difference calculation is very large, and due to the large difference in the size of dirt in different areas, the conventional detection method has the defects of troublesome classification and long detection time; compared with the current defect detection based on the detection template, the present method not only subtracts the actual grayscale image of the area to be detected from the detection template (reference grayscale image) and then compares the grayscale difference, but through step S3, the original image (actual grayscale image B) and the template (reference grayscale image A) are reduced and then subtracted, so that the calculation speed can be better improved by geometric times. In addition, in step S4, when no defects are detected, the zoom speed will be gradually reduced and re-detected, so it can better ensure that the detection needs of dirt defects of different sizes are met. DETAILED DESCRIPTION

[0019] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0020] Example 1

[0021] This embodiment provides a method for detecting contamination defects of patterned wafer pyramids, which comprises the following steps:

[0022] S1. Construct a detection template and obtain a reference grayscale image A of the area to be detected in the detection template, where A=I1[M,N]; I1[M,N] is the grayscale value of a pixel with M columns and N rows;

[0023] S2, obtaining the actual grayscale image B of the area to be detected, B = I2[M, N]; I2[M, N] is the grayscale value of the pixel point with M columns and N rows;

[0024] S3, simultaneously reducing the reference grayscale image A and the actual grayscale image B by n times, the reference grayscale image A after being reduced by n times is the grayscale image An, and the reference grayscale image B after being reduced by n times is the grayscale image Bn;

[0025] S4. Obtain the difference image ΔI between the grayscale image Bn and the grayscale image An n , ΔI n =A n -B n ; with ΔI n Pixels with grayscale values ​​greater than the set grayscale threshold are regarded as problem points, and the area of ​​all problem points connected in the actual grayscale image B is obtained as the defect area S;

[0026] When the defect area S is greater than the set area threshold, it is determined that there is a defect in the area to be inspected and the inspection is terminated;

[0027] When the defect area S is less than the set area threshold, n is assigned a value of n-1, and steps S3 and S4 are repeated to continue the detection until n=1;

[0028] S5. Output the detection results.

[0029] Due to the high density and large number of pattern wafer pyramids and the presence of groove structures, if there is dirt, the amount of difference calculation is very large, and because the size of dirt in different areas varies greatly, conventional detection methods have defects such as troublesome classification and long detection time. Compared with the current defect detection based on detection templates, this method not only subtracts the actual grayscale image of the area to be detected from the detection template (reference grayscale image) and then compares the grayscale difference, but through step S3, the original image (actual grayscale image B) and the template (reference grayscale image A) are reduced and then subtracted, so that the calculation speed can be better improved by geometric times. In addition, in step S4, when no defects are detected, the zoom speed will be gradually reduced and re-detected, so it can better ensure that the detection needs of dirt defects of different sizes are met.

[0030] In this embodiment, the value of n is set so that the pixel size of the reference grayscale image A after being reduced by n times is not less than 10. Therefore, the rationality of the detection can be better guaranteed. If the pixel size of the original image is 640, then n does not exceed 6; if the pixel size of the original image is 2560, then n does not exceed 8;

[0031] In this embodiment, the grayscale threshold is set to 25. A grayscale threshold greater than 25 will result in a decrease in detection capability, and a grayscale threshold less than 25 will result in an increase in overdetection.

[0032] In this embodiment, the area threshold is set to 15. If the area threshold is greater than 15, the detection capability will be reduced, and if it is less than 15, more over-detection will be caused.

[0033] In addition, this embodiment also provides a pattern wafer pyramid contamination defect detection device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the detection method described in this embodiment are implemented.

[0034] In addition, the present embodiment further provides a pattern wafer pyramid contamination defect detection system, which includes the pattern wafer pyramid contamination defect detection device described in the present embodiment.

[0035] In addition, this embodiment further provides a computer-readable medium on which a computer program is stored, and when the computer program is executed, the steps of the detection method described in this embodiment are implemented.

[0036] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on one or several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0037] The present invention and its implementation methods are described schematically above, and the description is not restrictive. The embodiments shown in the embodiments are only part of the implementation methods of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the embodiments and designs a structure and an implementation method similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for detecting contamination defects of patterned wafer pyramids, comprising the following steps: S1. Construct a detection template and obtain a reference grayscale image A of the area to be detected in the detection template, where A=I1[M,N]; I1[M,N] is the grayscale value of a pixel with M columns and N rows; S2, obtain the actual grayscale image B of the area to be detected, B = I2[M, N]; I2[M, N] is the grayscale value of the pixel point with M columns and N rows; S3, simultaneously reducing the reference grayscale image A and the actual grayscale image B by n times, the reference grayscale image A after being reduced by n times is the grayscale image An, and the reference grayscale image B after being reduced by n times is the grayscale image Bn; S4. Obtain the difference image ΔI between the grayscale image Bn and the grayscale image An n , ΔI n =A n -B n ; with ΔI n Pixels with grayscale values ​​greater than the set grayscale threshold are regarded as problem points, and the area of ​​all problem points connected in the actual grayscale image B is obtained as the defect area S; When the defect area S is greater than the set area threshold, it is determined that there is a defect in the area to be inspected and the inspection is terminated; When the defect area S is less than the set area threshold, n is assigned a value of n-1, and steps S3 and S4 are repeated to continue the detection until n=1; S5. Output the detection results.

2. The method for detecting contamination defects of patterned wafer pyramids according to claim 1, characterized in that: The value of n is set so that the pixel size of the reference grayscale image A after being reduced by n times is not less than 10.

3. The method for detecting contamination defects of patterned wafer pyramids according to claim 1, characterized in that: The grayscale threshold is set to 25.

4. The method for detecting contamination defects of patterned wafer pyramids according to claim 1, characterized in that: The area threshold is set to 15.

5. A pattern wafer pyramid contamination defect detection device, comprising a memory and a processor, wherein a computer program is stored in the memory, characterized in that: When the processor executes the computer program, the steps of the detection method according to any one of claims 1 to 4 are implemented.

6. Pattern wafer pyramid contamination defect detection system, characterized by: It includes the pattern wafer pyramid contamination defect detection device described in claim 5.

7. A computer readable medium having a computer program stored thereon, characterized in that: When the computer program is executed, the steps of the detection method according to any one of claims 1 to 5 are implemented.

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