US 11,990,311 B2
Charged particle source and charged particle beam device
Masahiro Fukuta, Tokyo (JP); and Kazuhiro Honda, Tokyo (JP)
Assigned to Hitachi High-Tech Corporation, Tokyo (JP)
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
Filed on Apr. 4, 2023, as Appl. No. 18/130,466.
Application 18/130,466 is a continuation of application No. 17/285,365, granted, now 11,651,929, previously published as PCT/JP2018/044634, filed on Dec. 5, 2018.
Prior Publication US 2023/0238205 A1, Jul. 27, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01J 37/073 (2006.01); H01J 37/28 (2006.01)
CPC H01J 37/073 (2013.01) [H01J 37/28 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A charged particle source configured to emit charged particles, the charged particle source comprising:
an emitter configured to emit charged particles from a tip end,
wherein the emitter has a shape of a spherical surface attached to a tip end of a needle portion,
wherein an angle over 90 degree is formed between a straight line and an optical axis of the charged particles, the straight line connecting an intersection between the needle portion and the spherical surface with a center of the spherical surface, and
wherein a distance between a first position on a surface of the spherical surface and the center is equal to a distance between the intersection and the center.