Shot noise reduction using frame averaging
AssigneeKLA Corporation
InventorsAbdurrahman Sezginer, Patrick McBride, Indrasen Bhattacharya, Robert M. Danen
Life of this patent
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Abstract
An inspection system includes a controller including one or more processors configured to execute program instructions. The program instructions cause the one or more processors to receive at least a first portion of a first set of repeat swaths of a first scan path of a sample. The program instructions cause the one or more processors to generate an image by averaging the first portion of the first set of repeat swaths. Averaging the first portion of the first set of repeat swaths reduces a noise in the image. The program instructions cause the one or more processors to detect one or more defects in an inspection region of the sample using the image.
Claims32
An inspection system comprising:
- a controller including one or more processors configured to execute program instructions causing the one or more processors to:
- receive at least a first portion of a first set of repeat swaths of a first scan path of a sample;
- align and scale the first portion of the first set of repeat swaths resulting in a common number of pixels and a common pixel location for each pixel of the first portion of the first set of repeat swaths;
- generate an image by averaging the first portion of the first set of repeat swaths;
- wherein averaging the first portion of the first set of repeat swaths reduces a noise in the image,
- wherein aligning the first portion of the first set of repeat swaths occurs before averaging the first portion;
- and
- detect one or more defects in an inspection region of the sample using the image.
An inspection system comprising:
- one or more optical inspection sub-systems;
- a controller communicatively coupled to the one or more optical inspection sub-systems, the controller including one or more processors to execute program instructions causing the one or more processors to:
- receive at least a first portion of a first set of repeat swaths of a first scan path of a sample;
- align and scale the first portion of the first set of repeat swaths resulting in a common number of pixels and a common pixel location for each pixel of the first portion of the first set of repeat swaths;
- generate an image by averaging the first portion of the first set of repeat swaths;
- wherein averaging the first portion of the first set of repeat swaths reduces a noise in the image,
- wherein aligning the first portion of the first set of repeat swaths occurs before averaging the first portion;
- and
- detect one or more defects in an inspection region of the sample using the image.
A method comprising:
- receiving at least a first portion of a first set of repeat swaths of a first scan path of a sample;
- aligning and scaling the first portion of the first set of repeat swaths resulting in a common number of pixels and a common pixel location for each pixel of the first portion of the first set of repeat swaths;
- generating an image by averaging the first portion of the first set of repeat swaths;
- wherein averaging the first portion of the first set of repeat swaths reduces a noise in the image,
- wherein aligning the first portion of the first set of repeat swaths occurs before averaging the first portion;
- and
- detecting one or more defects in an inspection region of the sample using the image.
Dependencies are inferred from the claim text.