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. 25, 1997
Filed:
Oct. 04, 1996
Masaru Wakabayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A method of manufacturing a semiconductor device furnished on a silicon substrate with a bipolar element part and a resistance element part formed of an impurity diffusion layer, having (a) a step of forming a first oxide film on said silicon substrate and on the component elements formed on said substrate throughout the entire surface thereof, (b) a step of selectively and sequentially removing the part of said first oxide film corresponding to the base region of said bipolar element part and the surface of said silicon substrate directly underlying said first oxide film and, at the same time, cleaning the freshly exposed surface, (c) a step of forming a second oxide film on said silicon substrate and said component elements formed thereon throughout the entire surface thereof thereby differentiating the thickness of the oxide film formed on said base region and the thickness of the oxide film formed on said resistance element part, and (d) a step of selectively and instantaneously implanting an ion into said bipolar element part and said resistance element part.