US 12,345,658 B2
Large-particle monitoring with laser power control for defect inspection
Anatoly Romanovsky, Palo Alto, CA (US); Zhiwei Xu, Sunnyvale, CA (US); Yury Yuditsky, Mountain View, CA (US); Yifeng Cui, Fremont, CA (US); and Mandar Paranjape, San Jose, CA (US)
Assigned to KLA CORPORATION, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Apr. 7, 2021, as Appl. No. 17/224,913.
Claims priority of provisional application 63/082,484, filed on Sep. 24, 2020.
Prior Publication US 2022/0091047 A1, Mar. 24, 2022
Int. Cl. G01N 21/95 (2006.01); G01N 21/88 (2006.01); H01L 21/66 (2006.01)
CPC G01N 21/9501 (2013.01) [G01N 21/8806 (2013.01); H01L 22/12 (2013.01); G01N 2021/8835 (2013.01)] 32 Claims
OG exemplary drawing
 
1. A method, comprising:
inspecting a semiconductor wafer using a main laser beam and a secondary laser beam, wherein the secondary laser beam leads the main laser beam and has lower power than the main laser beam;
detecting, using the secondary laser beam, a particle on the semiconductor wafer having a size that satisfies a threshold;
in response to detecting the particle, reducing the power of the main laser beam and the power of the secondary laser beam, wherein the particle passes through the main laser beam with the main laser beam at reduced power; and
after the particle has passed through the main laser beam with the main laser beam at the reduced power, restoring the power of the main laser beam and the power of the secondary laser beam in a controlled manner that is slower than a single step.