Patent ID: 9698216
Date: 2017-07-04
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a semiconductor layer; a first conductivity-type source region formed on a front surface portion of the semiconductor layer; a second conductivity-type channel region formed at a back surface side of the semiconductor layer with respect to the source region; a first conductivity-type drain region formed at the back surface side of the semiconductor layer with respect to the channel region; a source trench penetrating the source region and the channel region from the front surface of the semiconductor layer such that the source trench reaches the drain region; a gate insulating film being in contact with the channel region; and a gate electrode facing the channel region across the gate insulating film, wherein the source trench has a plurality of widths in a depth direction such that a planar area of the channel region is larger than that of the source region.