The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2003
Filed:
Nov. 07, 2001
Steven D. Golladay, Hopewell Junction, NY (US);
Michael S. Gordon, Lincolndale, NY (US);
Rodney A. Kendall, Ridgefield, CT (US);
Shinichi Kojima, Wappingers Falls, NY (US);
Werner Stickel, Ridgefield, CT (US);
Nikon Corporation, Tokyo, JP;
Abstract
The presence of magnetic fields from lenses and other (e.g. parasitic) sources at locations in a charged particle beam system such as the charged particle emitter, where the particles have little or no kinetic energy, creates disturbances of the charged particle trajectories, generating undesired angular momentum and resulting in excessive aberrations and associated adverse effects on system performance. Solutions are provided by suppression of these magnetic fields, by relocating the charged particle emitter away from the field source and/or counterbalancing the field with a bucking field. In addition, residual irrepressible field asymmetries are compensated by a suitable element such as a stigmator located at the correct location in the beam path, permitted by relocation of the charged particle emitter.