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:
Sep. 24, 2002
Filed:
Feb. 03, 2001
Michael Stuart Gordon, Lincolndale, NY (US);
Samuel Kay Doran, Wappingers Falls, NY (US);
Nikon Corporation, Tokyo, JP;
Abstract
A method and a apparatus are provided for operating an E-beam system including an E-beam source for generating an E-beam directed along a column axis and an electrode aligned with the column axis direct the E-beam towards means for measuring the E-beam. A signal proportional to leakage current emitted from the E-beam is generated. When the result of a comparison with a desired value is excessive, an excess leakage signal is generated. The excess leakage signal can be provided as an emergency output signal and/or produce an OFF signal for stopping production of the E-beam by turning OFF voltage/power sources for producing the E-beam in response to the excess leakage signal. Preferably, a filament is heated by an electric current and a cathode is bombarded with electrons from the filament to produce the E-beam. Then a filament control signal is employed for controlling the filament heating current.