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. 01, 1994
Filed:
May. 02, 1991
Ken Hattori, Tokyo, JP;
Kesayoshi Amano, Tokyo, JP;
Masao Nakajima, Kawasaki, JP;
Masayoshi Naito, Sendai, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Prior to a periphery exposing operation, a light emitting unit and a light receiving unit are retracted to a position separate from a wafer, and a calibrating operation is conducted in the retracted position utilizing a light shield plate different from the wafer to be exposed, thereby obtaining a servo control reference signal for the exposure. At the exposure of the periphery portion of the wafer, the exposure width is controlled according to the reference signal. It is therefore rendered possible to achieve exact peripheral exposure, including the intensity and intensity distribution of the exposing light beam immediately before the irradiation of the peripheral portion of the wafer.