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:
Dec. 17, 2002
Filed:
Dec. 22, 1999
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 2/742 ;
U.S. Cl.
CPC ...
G03B 2/742 ;
Abstract
An exposure apparatus includes a projection optical system for projecting exposure light, with which a reticle formed with a pattern is irradiated, onto a wafer, a stage for holding and aligning the wafer or reticle, an alignment optical system for outputting alignment light, a reflection mirror provided on the stage, and a plurality of interferometers for measuring the position of the stage by irradiating the reflection mirror with measurement light. The interferometer to be used to measure the position of the stage in a predetermined direction is switched to another in accordance with whether the stage is aligned to the projection optical system or to the alignment optical system.