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:
Jan. 20, 1976
Filed:
Aug. 08, 1974
Hiroyuki Kondo, Hinode, JA;
Atsuo Hotta, Higashiyamato, JA;
Akio Hayasaka, Kodaira, JA;
Michio Suzuki, Hino, JA;
Hitachi, Ltd., , JA;
Abstract
A method of manufacturing bipolar transistor elements in a semiconductor integrated circuit isolated by a silicon oxide film, comprises the steps of forming a semiconductor layer of one conductivity type on a semiconductor substrate of the opposite conductivity type, in which each collector region of the one conductivity type is formed, diffusing an impurity of the opposite conductivity type for each base region into the surface of the semiconductor layer of the one conductivity type, performing oxidation down to the surface of the semiconductor substrate by employing an oxidation-resisting film as a mask, to thereby form an isolating silicon oxide film, and diffusing an impurity of the one conductivity type for each emitter region into a selected part of the surface of the diffused semiconductor layer of the opposite conductivity type, whereby the base width of the bipolar transistor elements can be narrowed.