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:
Jan. 14, 1997
Filed:
Jul. 07, 1995
Applicant:
Inventors:
Roger L Verkuil, Wappinger Falls, NY (US);
Gregory S Horner, Solon, OH (US);
Thomas G Miller, Shaker Hts., OH (US);
Assignee:
Keithley Instruments, Inc., Cleveland, OH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01T / ;
U.S. Cl.
CPC ...
250326 ; 250324 ; 361224 ;
Abstract
A conductive screen is placed between a corona gun and the surface of a semiconductor wafer. The charge deposited on the wafer by the gun is controlled by a potential applied to the screen. A chuck orients the wafer in close proximity to the screen. A desired charge is applied to the wafer by first applying a surplus of one charge to the wafer and then depositing an opposite polarity charge until the potential of the wafer equals the potential of the screen.