US 12,347,643 B2
Multiple charged-particle beam apparatus and methods of operating the same using movable lenses
Weiming Ren, San Jose, CA (US); Xuedong Liu, San Jose, CA (US); Xuerang Hu, San Jose, CA (US); and Zhong-wei Chen, San Jose, CA (US)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Filed by ASML Netherlands B.V., Veldhoven (NL)
Filed on May 29, 2020, as Appl. No. 16/888,424.
Claims priority of provisional application 62/985,660, filed on Mar. 5, 2020.
Claims priority of provisional application 62/855,717, filed on May 31, 2019.
Prior Publication US 2020/0381212 A1, Dec. 3, 2020
Int. Cl. H01J 37/31 (2006.01); H01J 37/14 (2006.01); H01J 37/141 (2006.01); H01J 37/147 (2006.01); H01J 37/28 (2006.01); H01J 37/317 (2006.01)
CPC H01J 37/3177 (2013.01) [H01J 37/141 (2013.01); H01J 37/1478 (2013.01); H01J 37/28 (2013.01); H01J 2237/0435 (2013.01); H01J 2237/04922 (2013.01); H01J 2237/24564 (2013.01); H01J 2237/2817 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A charged particle beam apparatus to inspect a sample, the apparatus comprising:
a charged particle source configured to emit a charged particle beam along a primary optical axis;
a source conversion unit configured to convert the charged particle beam into a plurality of sub-beams to form a plurality of images of the charged particle source, the source conversion unit comprising:
an aperture-lens forming electrode plate configured to be at a first voltage;
an aperture lens plate configured to be at a second voltage that is different from the first voltage for generating a first electric field, which enables the aperture-lens forming electrode plate and the aperture lens plate to form a plurality of aperture lenses of an aperture lens array to respectively focus a plurality of beamlets of the charged particle beam;
a beam-limit aperture array positioned downstream of the aperture lens plate with respect to a path of the charged-particle beam and configured to limit beam currents of the plurality of beamlets exiting the aperture lens plate; and
an imaging lens configured to focus the plurality of beamlets on an image plane; and
an objective lens configured to focus the plurality of beamlets onto a surface of the sample and form a plurality of probe spots thereon.