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. 24, 2001
Filed:
Jun. 15, 1999
Shiro Nakanishi, Ohgaki, JP;
Nobuhiko Oda, Hashima, JP;
Sanyo Electric Co., Ltd., , JP;
Abstract
On a transparent substrate, on which is positioned a gate electrode, a silicon nitride film and a silicon oxide film are formed as gate insulating films, and furthermore a polycrystalline silicon film is formed as a semiconductor film to become an active region. A stopper is positioned on the polycrystalline silicon film to correspond to a gate electrode, and a silicon oxide film, a silicon nitride film, and a silicon oxide film are formed as interlayer insulating film so as to cover the stopper. Contact holes are formed in the layer insulating film to correspond to a source region and a drain region, and a source electrode and a drain electrode are positioned through these contact holes. Since the silicon oxide film having a fast etching rate is formed on the silicon nitride film having a slow etching rate, the etching from the silicon oxide film above the silicon nitride film dominates when forming the contact holes in the layer insulating film so that the etched shape of the silicon nitride film assumes a tapered shape widening toward the top.