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:
Jul. 05, 1988
Filed:
Nov. 17, 1986
Applicant:
Inventors:
Willi R Bohm, Unterhaching, DE;
Hans-Christian Schaber, Graefelfing, DE;
Assignee:
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437191 ; 437233 ; 437228 ; 156657 ; 357 34 ; 357 59 ;
Abstract
Self-adjusted bipolar transistors having reduced extrinsic base resistance are produced by forming an emitterterminal from a polysilicon layer structure and etching free the polysilicon layer structure using the emitter layer structure as a mask. Sidewall insulating layers are provided with a metallically conductive layer. This layer is self-adjusting in relation to the emitter zone and surrounds the emitter in an annular formation. The structure improves the foursided base wiring around the emitter and is used in the production of highly integrated bipolar circuits.