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. 21, 1995
Filed:
Oct. 20, 1992
Hirotaka Nishizawa, Akishima, JP;
Seiichiro Azuma, Akishima, JP;
Kazuaki Ootoshi, Ohme, JP;
Masataka Miyama, Fuchu, JP;
Shuji Kawata, Ohme, JP;
Osamu Kasahara, Hinode, JP;
Sinichi Suzuki, Ohme, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi VLSI Engineering Corp., Kodaira, JP;
Abstract
There is provided a semiconductor integrated circuit device having bipolar transistors each composed of an emitter region, base region, and collector region arranged vertically on a semiconductor substrate, said collector region having a plane figure, with the square corners thereof cut off. To be concrete, the buried collector region having a high concentration of impurity has its square corners cut off and the base region formed on the major surface of the epitaxial layer formed on said buried collector region has also its square corners cut off. The bipolar transistor having such a plane figure has a reduced parasitic capacity and an increased operating speed. A manufacturing method is also provided capable of producing a highly reliable groove isolation structure with a low dielectric constant.