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:
May. 23, 1989
Filed:
Jun. 03, 1987
Toshikazu Umatate, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
in the production of semiconductor devices, for example, high-accuracy, high-speed alignment of different exposure areas of a wafer with respect to a reticle is achieved by the use, for each exposure area, of a predetermined number of sampling areas that are selected so as to be adjacent to a selected exposure area. A position detector produces position information signals regarding the positions of a plurality of sampling areas and stores the position information signals in a memory. Design data indicating positions of a plurality of sampling areas are also stored in memory. A calculator calculates a correction value for the selected exposure area on the basis of the position information signals and the design data for the selected sampling areas. The wafer is then displaced relative to the reticle in accordance with the correction value and design data for the selected exposure area.