US 12,451,324 B2
Leveling sensor in multiple charged-particle beam inspection
Jian Zhang, San Jose, CA (US); Yan Wang, San Jose, CA (US); Liang Tang, San Jose, CA (US); and Yixiang Wang, Fremont, CA (US)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Appl. No. 17/911,398
Filed by ASML Netherlands B.V., Veldhoven (NL)
PCT Filed Feb. 25, 2021, PCT No. PCT/EP2021/054623
§ 371(c)(1), (2) Date Sep. 13, 2022,
PCT Pub. No. WO2021/180473, PCT Pub. Date Sep. 16, 2021.
Claims priority of provisional application 62/989,488, filed on Mar. 13, 2020.
Prior Publication US 2023/0096657 A1, Mar. 30, 2023
Int. Cl. H01J 37/20 (2006.01); G01B 11/06 (2006.01); H01J 37/21 (2006.01); H01J 37/22 (2006.01); H01J 37/244 (2006.01)
CPC H01J 37/20 (2013.01) [G01B 11/0608 (2013.01); H01J 37/21 (2013.01); H01J 37/222 (2013.01); H01J 37/244 (2013.01); H01J 2237/20292 (2013.01); H01J 2237/24578 (2013.01); H01J 2237/2482 (2013.01); H01J 2237/2817 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A charged-particle beam inspection system comprising:
a stage configured to hold a sample; and
a leveling sensor configured to determine a vertical displacement of the sample and comprising:
a light source configured to project a first pattern onto the sample; and
a detector configured to capture an image of a projected pattern after the first pattern is projected on the sample,
wherein the first pattern comprises an irregularity to enable a determination of the vertical displacement of the sample.