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:
Aug. 31, 2004
Filed:
Sep. 21, 2001
Applicant:
Inventor:
Fuyuhiko Inoue, San Mateo, CA (US);
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B 9/02 ;
U.S. Cl.
CPC ...
G01B 9/02 ;
Abstract
This invention relates to an apparatus and method for positioning dual stages during semiconductor wafer processing. More particularly, the invention facilitates the use of interferometers to determine the positions of both wafer stages at all times during processing. While the movement of a typical twin stage apparatus causes one of the stages to eclipse the other and requires the addition of a significant number of additional interferometers, this invention minimizes the number of interferometers necessary through dimensioning the stages so that one stage never totally eclipses the other.