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:
Feb. 04, 2014
Filed:
Jun. 13, 2011
Applicant:
Hitoshi Uemura, Tokyo, JP;
Inventor:
Hitoshi Uemura, Tokyo, JP;
Assignee:
Mitsubishi Electric Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 29/66 (2006.01); H01L 29/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
A carrier is prevented from being stored in a guard ring region in a semiconductor device. The semiconductor device has an IGBT cell including a base region and an emitter region formed in an n− type drift layer, and a p type collector layer arranged under the drift layer with a buffer layer interposed therebetween. A guard ring region having a guard ring is arranged around the IGBT cell. A lower surface of the guard ring region has a mesa structure provided by removing the collector layer.