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:
May. 28, 1991
Filed:
Mar. 30, 1990
Tohru Nakamura, Hoya, JP;
Takao Miyazaki, Hachioji, JP;
Susumu Takahashi, Tokyo, JP;
Ichiro Imaizumi, Tokyo, JP;
Takahiro Okabe, Tokyo, JP;
Minoru Nagata, Kodaira, JP;
Masao Kawamura, Fuchu, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a process for making a bipolar transistor which comprises an n-type Si semiconductor body having a convex portion, an insulation film covering the surface of the semiconductor body other than the convex portion, and a p-type polycrystalline Si layer formed on the insulation film. A p-type region formed in the convex portion serves as an intrinsic base region, the polycrystalline Si layer serves as an extrinic base region, an n-type region formed in the intrinsic base region serves as an emitter region, and the body serves as a collector region.