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:
Oct. 31, 2000
Filed:
Nov. 05, 1998
Applicant:
Inventor:
Hajime Kimura, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438275 ; 438197 ; 438258 ;
Abstract
A first gate oxide film is formed on a surface of a silicon substrate. A first polycrystalline silicon film is formed on the first gate oxide film, and patterned so that its side surface is tapered. Silicon oxide film exposed through the first polycrystalline silicon is removed, and a second silicon oxide film having film thickness different from that of the first silicon oxide film is formed by thermal oxidation. Thus, dual gate oxide is manufactured. Accordingly, a method of manufacturing a semiconductor device is provided which can improve reliability of the transistor and can improve production yield, by suppressing generation of foreign matters.