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. 08, 1991
Filed:
Mar. 30, 1988
Applicant:
Inventor:
Akio Kayanuma, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 50 ; 357 20 ; 357 34 ; 357 52 ; 357 59 ;
Abstract
A bipolar integrated circuit having a polysilicon contact (26) to a heavily doped graft base region 24g which is spaced from oxide isolation walls 22 by a distance sufficiently small that in operation, the surface portion 37 of the collector region 23 is fully depleted from the graft base region 24g to the oxide isolation 22, so that base-collector capacitance is reduced due to the graft base being smaller than the oxide isolated island and by the absence of capacitance between the sides of the graft base region and the collector, while capacitance between the polysilicon contact 26 and the collector is also decreased by the depleted surface portion 37 of the collector.