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. 20, 1993
Filed:
Jul. 22, 1991
Shinji Suzuki, Kawasaki, JP;
Ushio Denki, Tokyo, JP;
Abstract
A method of exposing a peripheral part of the wafer is used for a fine pattern formation process in the processing of ICs, LSIs and other electronic elements, to remove, in a development step, an unnecessary portion of a photoresist coated on a semiconductor substrate, typically a silicon wafer, or a substrate consisting of a dielectric, a metal or an insulator. A peripheral part of the wafer is exposed to light led by an optical fiber light guide. The same area is exposed to light at least twice in a predetermined time interval. The illumination intensity of light in a wavelength range necessary for the first exposure is set to be lower than that for the second and following exposures. In the first exposure, the wafer may be held in a heated state.