Patent ID: 8735906
Filing Date: 2014-05-27
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor layer of a first conductivity type made of SiC; a body region of a second conductivity type formed on a surface layer portion of the semiconductor layer; a gate trench dug down from a surface of the semiconductor layer with a bottom surface formed on a portion of the semiconductor layer under the body region; a plurality of source regions of the first conductivity type formed on a surface layer portion of the body region adjacent to side surfaces of the gate trench; a gate insulating film formed on the bottom surface and side surfaces of the gate trench so that the thickness of a bottom portion on the bottom surface is greater than the thickness of side portions on the side surfaces; a gate electrode embedded in the gate trench through the gate insulating film; and an implantation layer formed on a portion of the semiconductor layer extending from the bottom surface of the gate trench to an intermediate portion of the semiconductor layer in the thickness direction by implantation of a second conductivity type impurity; wherein side portions of the gate insulating film include at least one first portion adjacent to the plurality of source regions on the side surfaces of the gate trench and at least one second portion other than the at least one first portion thereof; wherein a thickness T wherein the first portions of the gate insulating film protrude along with the surface of the semiconductor layer on both of an inner side and an outer side of the gate trench with respect to the side surfaces of the gate trench inside the gate trench; and wherein the ratio (T