Publication number: 20150332889
Abstract: A multipole lens (100) which can produce static magnetic fields showing different strengths in the direction of travel of an electron beam has lens subasssemblies (10a, 10b, 10c) stacked on top of each other. The lens subassemblies (10a, 10b, 10c) have yokes (14a, 14b, 14c), respectively, and polar elements (12a, 12b, 12c), respectively. The polar elements (12a, 12b, 12c) have base portions (13a, 13b, 13c), respectively, magnetically coupled to the yokes (14a, 14b, 14c), respectively, and front end portions (11a, 11b, 11c), respectively, magnetically coupled to the base portions (13a, 13b, 13c), respectively. Magnetic field separators (20, 22) made of a nonmagnetic material are mounted between the front end portions (11a, 11b, 11c) which are successively adjacent to each other in the direction of stacking of the lens subassemblies (10a, 10b, 10c).
Type:
Application
Filed:
April 16, 2015
Publication date:
November 19, 2015
Inventor:
Hidetaka Sawada