US 12,278,081 B2
System and method for alignment of secondary beams in multi-beam inspection apparatus
Qingpo Xi, Fremont, CA (US); Xuerang Hu, San Jose, CA (US); Xuedong Liu, San Jose, CA (US); Weiming Ren, San Jose, CA (US); and Zhong-Wei Chen, San Jose, CA (US)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Appl. No. 17/598,841
Filed by ASML Netherlands B.V., Veldhoven (NL)
PCT Filed Mar. 6, 2020, PCT No. PCT/EP2020/055959
§ 371(c)(1), (2) Date Sep. 27, 2021,
PCT Pub. No. WO2020/193102, PCT Pub. Date Oct. 1, 2020.
Claims priority of provisional application 62/824,954, filed on Mar. 27, 2019.
Prior Publication US 2022/0189726 A1, Jun. 16, 2022
Int. Cl. H01J 37/05 (2006.01); H01J 37/147 (2006.01)
CPC H01J 37/05 (2013.01) [H01J 37/1474 (2013.01); H01J 2237/1501 (2013.01); H01J 2237/1508 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A multi-beam apparatus for inspecting a sample, comprising:
a primary projection system configured to project a primary particle beam onto the sample, comprising:
an adjustable charged particle beam separator configured to change a path of a secondary particle beam at an effective bending point, comprising:
a first Wien filter aligned with a primary optical axis, wherein the first Wien filter is independently controllable via a first excitation input; and
a second Wien filter aligned with the primary optical axis, wherein the second Wien filter is independently controllable via a second excitation input, and
a secondary projection system comprising a deflector and a lens that are configured to project the secondary particle beam onto a detection surface,
wherein the adjustable charged particle beam separator is configured to enable the effective bending point to be moved based on the first excitation input and the second excitation input, which are adjusted based on alignment characteristics of the secondary projection system.