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. 14, 1992
Filed:
Nov. 08, 1990
Applicant:
Inventors:
Assignee:
BBC Brown Boveri AG, Baden, CH;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
437-6 ; 437139 ; 437152 ;
Abstract
In a high-reverse-voltage GTO thyristor, a negative beveling (6) with comparatively high beveling angle (.alpha.) is possible as edge contouring as a result of separating the p-type base layer into a central p-type base layer (4) of small depth and high edge concentration and a p-type base edge layer (5) of greater depth and lower edge concentration. The production of the two p-type base layers (4, 5) is preferably carried out by simultaneous diffusion of two acceptors with different diffusion constants.