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. 19, 1999
Filed:
Jan. 17, 1997
Applicant:
Inventor:
Takayuki Gomi, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257197 ; 257198 ; 257554 ; 257571 ; 257588 ; 257592 ;
Abstract
A mesa bipolar transistor comprising a collector layer formed on a surface of a substrate, a base layer disposed on the substrate so as to be joined to the collector layer, an emitter layer disposed on the base layer is further provided with a sub base layer comprising at least one of a polysilicon layer containing impurities, a metallic silicide, and a diffused layer formed on the surface of the substrate and being disposed under or on the external base region which is a region of the base layer lateral to that under the emitter layer so that the thickness of the external base region is increased to provide high conductivity.