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:
Nov. 17, 1998
Filed:
Oct. 17, 1996
Applicant:
Inventors:
Lee H Veneklasen, Castro Valley, CA (US);
Lydia J Young, Palo Alto, CA (US);
Assignee:
Etec Systems, Inc., Hayward, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
250310 ; 2505051 ;
Abstract
A conical shaped baffle aperture reduces beam position drift due to electrostatic charging of insulating contamination layers on beam tube walls of a charged particle beam system. The geometric cone angle, aperture size and apex location of the baffle with respect to the source of contamination and secondary radiation are selected so that the inner walls of the baffle and the beam itself are invisible from the source, and therefore remain free of the insulating contamination layers that would otherwise cause charging drift.