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:
Feb. 06, 1990
Filed:
Nov. 15, 1988
Kazuo Takeda, Gunma, JP;
Nobuyuki Sekikawa, Gunma, JP;
Katsuhiro Hayasaka, Gunma, JP;
Chikao Fujunuma, Gunma, JP;
Nobuo Itoh, Gunma, JP;
Tetsuya Kubota, Gunma, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A method of fabricating a semiconductor integrated circuit comprises the steps of: forming buried layers in predetermined regions of a semiconductor substrate; forming an epitaxial layer covering the substrate and the buried layers; forming isolation regions dividing the epitaxial layer into a plurality of islands; selectively implanting ions to form a base region of a vertical bipolar transistor in a surface layer of one island and simultaneously to form a resistor region in a surface layer of another island; and selectively diffusing impurities into a surface layer of the base region, to form an emitter region of the vertical bipolar transistor.