Image processing method, image processing apparatus, and learning method

Patent metadata

Field	Value
Publication number	US-2026099915-A1
Application number	US-202519349572-A
Country	US
Kind code	A1
Filing date	Oct 3, 2025
Priority date	Oct 4, 2024
Publication date	Apr 9, 2026
Grant date	—

Abstract

An image processing method includes: a process of acquiring an inspection image, which is an image captured by illuminating, by critical illumination, an inspection target area of an object to be inspected; a process of acquiring illumination profile information indicating an illumination profile at the time of image capturing; a process of generating a reference image based on design information of the object to be inspected; and a process of inspecting the inspection target area by comparing the inspection image with the reference image, in which, in the process of generating the reference image, by using the illumination profile information, different reference images are generated for areas that show a common structure in the design information.

First claim

What is claimed is:

1 . An image processing method comprising:
a process of acquiring an inspection image, which is an image captured by illuminating, by critical illumination, an inspection target area of an object to be inspected; a process of acquiring illumination profile information indicating an illumination profile at the time of image capturing; a process of generating a reference image based on design information of the object to be inspected; and a process of inspecting the inspection target area by comparing the inspection image with the reference image, wherein, in the process of generating the reference image, by using the illumination profile information, different reference images are generated for areas that show a common structure in the design information.

2 . The image processing method according to claim 1 , wherein, in the process of generating the reference image, the reference image is generated by inputting a design image which is based on the design information and the illumination profile information regarding the inspection image to a machine learning model that is learned in advance.

3 . The image processing method according to claim 2 , wherein the machine learning model is a model that is learned using learning data, which is a set of a learning image, which is an image captured by illuminating a learning sample by critical illumination, a sample design image, which is an image of the learning sample drawn in accordance with design information of the learning sample, and illumination profile information indicating an illumination profile when the learning image is captured.

4 . The image processing method according to claim 1 , wherein
in the process of generating the reference image,
a design image which is based on the design information is corrected, by an optical simulation that uses the illumination profile information regarding the inspection image, to a design image on which the illumination profile information is reflected, and
the reference image is generated by inputting the corrected design image to a machine learning model learned in advance.

5 . The image processing method according to claim 4 , wherein the machine learning model is a model learned by using learning data, which is a set of a learning image, which is an image captured by illuminating a learning sample by critical illumination, and a sample design image, which is an image of the learning sample drawn in accordance with design information of the learning sample.

6 . The image processing method according to claim 1 , wherein, in the process of generating the reference image, the reference image is generated by inputting a design image which is based on the design information to one of a plurality of machine learning models learned in advance that has been selected based on the illumination profile information regarding the inspection image.

7 . The image processing method according to claim 6 , wherein
each of the plurality of machine learning models is a model that is learned using learning data, which is a set of a learning image, which is an image captured by illuminating a learning sample by critical illumination, and a sample design image which is based on design information of the learning sample, and
in the learning data used for the learning, a characteristic of an illumination profile of the critical illumination is different for each of the machine learning models.

8 . The image processing method according to claim 1 , wherein
in the process of acquiring the inspection image, the inspection image captured by using a first detector is acquired,
the first detector is a TDI sensor that has image pickup elements arranged in a first direction and a second direction and accumulates electrical charges from the plurality of respective image pickup elements arranged in the second direction, and
the illumination profile information indicates a luminance intensity distribution of illumination light in the first direction.

9 . The image processing method according to claim 1 , wherein
in the process of acquiring the inspection image, the inspection image captured by using a first detector is acquired, and
the illumination profile information is an image obtained by capturing, by a second detector, an image obtained by imaging light from a light source.

10 . An image processing apparatus comprising:
at least one memory storing instructions; and at least one processor configured to execute the instructions to:
acquire an inspection image, which is an image captured by illuminating, by critical illumination, an inspection target area of an object to be inspected;
acquire illumination profile information indicating an illumination profile at the time of image capturing;
generate a reference image based on design information of the object to be inspected; and
inspect the inspection target area by comparing the inspection image with the reference image,
wherein, in generating the reference image, different reference images are generated for areas that show a common structure in the design information by using the illumination profile information.

11 . The image processing apparatus according to claim 10 , wherein the processor is configured to execute the instructions to generate the reference image by inputting a design image which is based on the design information and the illumination profile information regarding the inspection image to a machine learning model that is learned in advance.

12 . The image processing apparatus according to claim 11 , wherein the machine learning model is a model that is learned using learning data, which is a set of a learning image, which is an image captured by illuminating a learning sample by critical illumination, a sample design image, which is an image of the learning sample drawn in accordance with design information of the learning sample, and illumination profile information indicating an illumination profile when the learning image is captured.

13 . The image processing apparatus according to claim 10 , wherein the processor is configured to execute the instructions to:
correct, by an optical simulation that uses the illumination profile information regarding the inspection image, a design image which is based on the design information to a design image on which the illumination profile information is reflected; and generate the reference image by inputting the corrected design image to a machine learning model learned in advance.

14 . The image processing apparatus according to claim 13 , wherein the machine learning model is a model that is learned using learning data, which is a set of a learning image, which is an image captured by illuminating a learning sample by critical illumination, and a sample design image, which is an image of the learning sample drawn in accordance with design information of the learning sample.

15 . The image processing apparatus according to claim 10 , wherein, the processor is configured to execute the instructions to generate the reference image by inputting a design image which is based on the design information to one of a plurality of machine learning models learned in advance that has been selected based on the illumination profile information regarding the inspection image.

16 . The image processing apparatus according to claim 15 , wherein
each of the plurality of machine learning models is a model that is learned using learning data, which is a set of a learning im

Assignees

• Lasertec Corp

Inventors

• Kobayashi Mizuki

Classifications

• G06T7/0006

  using a design-rule based approach · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title

• G06T2207/20081

  Training; Learning · CPC title

• G06T7/001 Primary

  using an image reference approach · CPC title