Patent ID: 9607805
Date: 2017-03-28
CPC Classifications: H01J

Claim:
1. A source-conversion unit of an electron source, comprising: an image-forming means; and a beamlet-limit means with a plurality of beamlet-limit openings, wherein said image-forming means comprises a micro-deflector array with a plurality of micro-deflectors and a micro-compensator array with a plurality of micro-compensators, and each micro-deflector is aligned with one micro-compensator and one beamlet-limit opening, wherein said each micro-deflector deflects one beamlet of an electron beam generated by said electron source to forms one virtual image thereof and enter said one micro-compensator along an optical axis thereof, said one micro-compensator influences said one beamlet to add certain amounts of astigmatism aberration and/or field curvature aberration to said virtual image, and said one beamlet-limit opening cuts off peripheral electrons of said one beamlet and thereby limiting a current thereof.