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:
Oct. 06, 1992
Filed:
Sep. 10, 1990
Applicant:
Inventors:
Assignee:
BBC Brown, Boveri AG, Baden, CH;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
357 38 ; 357 22 ; 357 39 ; 357 52 ; 357 55 ; 357 37 ; 357 36 ;
Abstract
A gate-turn-off power semiconductor device of the GTO or FCTh type, having a control zone of alternately arranged finely subdivided cathode fingers and gate trenches, wherein the gate trenches are constructed as narrow deep slots, preferably by a crystal-direction-selective wet chemical etching process, while the original substrate surface is retained in the remaining area of the semiconductor substrate. Compared with the conventional 'recessed-gate' construction, this quasi-planar construction offers a number of advantages in the electrical behavior, in the integration of auxiliary functions and in the production.