US 12,106,933 B2
Method to correct first order astigmatism and first order distortion in multi-beam scanning electron microscopes
Jan Stopka, Brno (CZ); and Bohuslav Sed'a, Brno (CZ)
Assigned to FEI Company, Hillsboro, OR (US)
Filed by FEI Company, Hillsboro, OR (US)
Filed on Mar. 14, 2022, as Appl. No. 17/694,549.
Claims priority of provisional application 63/169,060, filed on Mar. 31, 2021.
Claims priority of provisional application 63/169,064, filed on Mar. 31, 2021.
Prior Publication US 2022/0328284 A1, Oct. 13, 2022
Int. Cl. H01J 37/28 (2006.01); H01J 37/10 (2006.01); H01J 37/153 (2006.01)
CPC H01J 37/28 (2013.01) [H01J 37/10 (2013.01); H01J 37/153 (2013.01); H01J 2237/0453 (2013.01); H01J 2237/1532 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An apparatus comprising:
an electron source coupled to provide an electron beam;
an aperture plate comprising an array of apertures, the aperture plate arranged to form an array of electron beamlets from the electron beam;
an electron column including a plurality of lenses and first and second stigmators, the electron column coupled to direct the array of electron beamlets toward a sample, wherein the first and second stigmators are arranged and excited to correct both astigmatism and linear distortion,
wherein the first stigmator is arranged at a common beam crossover plane.