Patent ID: 9293575
Filing Date: 2016-03-22
CPC Classification: H01L

Claim Text:
1. A semiconductor device, comprising: a semiconductor layer made of SiC; a source region of a first conductivity type formed in the semiconductor layer, the source region forming a surface of the semiconductor layer; a body region of a second conductivity type formed in the semiconductor layer, the body region being in contact with the source region from a side of a back surface of the semiconductor layer; a drain region of a first conductivity type formed in the semiconductor layer, the drain region being in contact with the body region from the side of the back surface of the semiconductor layer; a gate trench dug down in the semiconductor layer from the surface thereof, the gate trench passing through the source region and the body region and the deepest portion thereof reaching the drain region; a gate insulating film formed on an inner surface of the gate trench; a gate electrode embedded in the gate trench on the gate insulating film; a source trench dug down in the semiconductor layer from the surface thereof, the source trench passing through the source region and the body region, and the deepest portion thereof reaching a first conductivity type part of the drain region; and a conductive material embedded in the source trench, the conductive material having a first layer conforming to a side surface and a bottom surface of the source trench and a second layer formed on the first layer; wherein the second layer includes at least a lower layer conforming to the first layer to define a space inside the source trench, and an upper layer embedded in the space.