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:
Nov. 02, 2004
Filed:
Mar. 07, 2003
Kazuya Ota, Ota-ku, JP;
Nikon Corporation, Tokyo, JP;
Abstract
When a mask is irradiated obliquely with light from a lighting system, the light reflected from the mask is projected onto a wafer through a projection optical system, and the pattern of the mask is transferred to the wafer. If the magnification of the projection optical system changes because of a vertical movement of the mask, a control unit detects the projection position of the mask pattern image on a stage by an aerial image sensor and also detects a mark on the aerial image sensor by a mark detector so as to determine the baseline of the mark detector. Thus, the positional shift of the projection position of the mask pattern image on the wafer due to the change in magnification is corrected to sufficiently restrict or prevent alignment inaccuracy associated with the change in magnification.