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:
Dec. 01, 2009
Filed:
Mar. 17, 2005
Katsunori Asano, Osaka, JP;
Yoshitaka Sugawara, Osaka, JP;
Katsunori Asano, Osaka, JP;
Yoshitaka Sugawara, Osaka, JP;
The Kansai Electric Power Co., Inc., Osaka-shi, Osaka, JP;
Abstract
SiC-IGBTs, which have an inversion-type channel with high channel resistance and have high on-voltage due to an influence from the surface state of the interface between a gate insulating film and a base layer, are required to decrease the on-voltage. An embedded collector region is partially formed in a base layer which is formed on an emitter layer of a SiC semiconductor. A channel layer is formed on the base layer and the embedded collector region to constitute an accumulation-type channel. Consequently, at on time, holes are accumulated in the upper layer portion of the channel layer so that a low-resistant channel is formed. Current by the holes flows to the emitter layer through a channel from the collector region and becomes a base current for an npn transistor composed of the embedded collector region, the base region and the emitter region.