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:
Apr. 17, 2001
Filed:
Sep. 11, 1998
Tetsuya Oshino, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
The electron beam projection exposure apparatus of the present invention reduces the incidence of defects in patterns formed by exposure on a substrate and includes an illumination optical system for generating an electron beam, a mask placed in a prescribed location including a mask stage for aligning and scanning the mask, a projection-imaging optical system for projecting an image of a pattern formed on the mask onto a substrate with the substrate including a substrate stage for positioning and scanning the substrate. The electron beam projection exposure apparatus further includes at least one filter placed in the proximity of the mask for filtering dust and for preventing dust particles from inhibiting the passage of the electron beam to said substrate.