US 12,190,500 B2
Detecting defects on specimens
Chunwei Song, Shanghai (CN); Siqing Nie, Shanghai (CN); Weifeng Zhou, Shanghai (CN); Xiaochun Li, San Jose, CA (US); and Sangbong Park, Danville, CA (US)
Assigned to KLA Corp., Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Mar. 5, 2023, as Appl. No. 18/178,519.
Prior Publication US 2024/0296545 A1, Sep. 5, 2024
Int. Cl. G06T 7/00 (2017.01); G06V 10/74 (2022.01)
CPC G06T 7/001 (2013.01) [G06V 10/74 (2022.01); G06T 2207/10024 (2013.01); G06T 2207/10061 (2013.01); G06T 2207/20224 (2013.01); G06T 2207/30148 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system configured for detecting defects on a specimen, comprising:
an inspection subsystem configured for generating images for a specimen including a test image and two or more other images corresponding to the test image; and
a computer subsystem configured for:
computing first and second candidate reference images from different combinations of at least two of the test image and the two or more other images;
selecting at least a portion of the first candidate reference image corresponding to a first portion of the test image and a portion of the second candidate reference image corresponding to a second portion of the test image;
combining the selected portions of the first and second candidate reference images without modifying the selected portions of the first and second candidate reference images to thereby generate a final reference image;
generating a difference image by comparing the test image to the final reference image; and
detecting defects in the test image by applying a defect detection method to the difference image.