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:
Jul. 18, 2000
Filed:
Mar. 25, 1998
Noriaki Tokuda, Kanagawa-ken, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Even when there is a large change in unevenness on the surface of an area to be exposed, scanning exposure is carried out without reducing the throughput by accurately bringing the surface of the area into focus to the image plane. Focus position measuring areas (15F and 15R) are set apart from a slit-shaped illumination field (3) by respective sections (16F and 16R) with a predetermined width in the scanning direction. To carry out scanning exposure for a shot area on a wafer, the shot area is covered by the measuring area (15F), for example, at an approach start point of the wafer, and the focus position of the surface of the shot area is measured at detecting points (P.sub.11 to P.sub.53) in the measuring area (15F). On the basis of the result of the measurement, controlled variables for the surface position of the wafer are determined to bring the wafer surface in the illumination field (3) into focus to the image plane during scanning exposure by an autofocusing method and an autoleveling method.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile