Patent ID: 9117872
Filing Date: 2015-08-25
Classification: H01L

Abstract:
1. A semiconductor device comprising: a p-type collector region; an n-type drift region arranged on the collector region; a p-type base region arranged on the drift region; an n-type emitter region arranged on the base region; a gate oxide film arranged on a bottom surface and side surface of a trench that extends from an upper surface of the emitter region and penetrates the emitter region and the base region; a gate electrode embedded in an inside of the trench so as to be opposed to the base region while interposing the gate oxide film therebetween; and an n-type carrier accumulation region having a higher impurity concentration than the drift region, the carrier accumulation region arranged in at least an area between the drift region and the base region, wherein a position of a lower surface of the base region is shallower in a region brought into contact with the gate oxide film than in a region spaced apart from the gate oxide film, a position of an upper surface of the carrier accumulation region is shallower in the region brought into contact with the gate oxide film than in the region spaced apart from the gate oxide film, and a position of the lower surface of the carrier accumulation region is deeper in the region brought into contact with the gate oxide film than in the region spaced apart from the gate oxide film.