US 12,387,905 B2
Apparatus and method for detecting one or more scanning charged particle beams
Lenard Maarten Voortman, Delft (NL); and Andries Pieter Johan Effting, Delft (NL)
Assigned to DELMIC IP B.V., Delft (NL)
Appl. No. 17/615,414
Filed by DELMIC IP B.V., Delft (NL)
PCT Filed Jun. 3, 2020, PCT No. PCT/NL2020/050358
§ 371(c)(1), (2) Date Nov. 30, 2021,
PCT Pub. No. WO2020/246881, PCT Pub. Date Dec. 10, 2020.
Claims priority of application No. 2023249 (NL), filed on Jun. 3, 2019.
Prior Publication US 2022/0238297 A1, Jul. 28, 2022
Int. Cl. H01J 37/28 (2006.01); H01J 37/147 (2006.01); H01J 37/20 (2006.01); H01J 37/22 (2006.01); H01J 37/244 (2006.01); H01J 37/26 (2006.01)
CPC H01J 37/226 (2013.01) [H01J 37/1474 (2013.01); H01J 37/20 (2013.01); H01J 37/224 (2013.01); H01J 37/244 (2013.01); H01J 37/265 (2013.01); H01J 37/28 (2013.01); H01J 2237/2445 (2013.01); H01J 2237/2808 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An apparatus for inspecting a sample, wherein the apparatus comprises:
a sample holder for holding the sample,
a charged particle column for generating and directing one or more primary charged particle beams towards the sample holder,
wherein said charged particle column is configured for focusing said one or more primary charged particle beams at one or more charged particle beam spots onto the sample,
a scanning unit for scanning the one or more primary charged particle beams over the sample in a scanning direction,
a photon detector for detecting photons created by said one or more focused primary charged particle beams when said one or more primary charged particle beams impinge on the sample or when said one or more primary charged particle beams impinge onto a layer of luminescent material after transmission of said one or more primary charged particle beams through the sample,
an optical assembly for projecting or imaging at least part of said photons from said one or more charged particle beam spots along an optical beam path onto one or more light spots on said photon detector, wherein the optical assembly comprises a mirror or a polygon mirror arranged in the optical beam path between the sample holder and the photon detector, wherein the mirror or the polygon mirror is configured for reflecting the optical beam path at a deflection angle between 0 and 180 degrees, and
a shifting unit for shifting the one or more light spots and/or the photon detector with respect to each other, wherein the shifting unit comprises a mirror actuator which is configured for adjusting a tilting angle of the mirror or a rotating actuator which is configured for rotating the polygon mirror, wherein said shifting unit is configured for at least partially compensating a movement of the one or more primary charged particle beams on the sample or on the layer of luminescent material due to the scanning of the one or more charged particle beam spots by the scanning unit.