Patent ID: 9570601
Date: 2017-02-14
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: (a) a substrate of a first conductivity type which has a first main surface and a second main surface opposite to the first main surface, and is made of a semiconductor material having a larger band gap than silicon; (b) a drift layer of the first conductivity type formed on the first main surface of the substrate; (c) a well region of a second conductivity type which has a first depth from a top surface of the drift layer, and is obtained by introducing a first impurity of the second conductivity type different from the first conductivity type into the drift layer; (d) a source region of the first conductivity type which has a second depth from the top surface of the drift layer, and is disposed in the well region being separated from an end portion of the well region, and into which a second impurity of the first conductivity type is introduced; (e) a gate insulating film which is in contact with, at least, the well region between the drift layer and the source region; (f) a gate electrode which is in contact with the gate insulating film; and (g) a drain region of the first conductivity type formed on the second main surface side of the substrate, wherein the gate electrode includes: wherein the first material and the second material have different thermal expansion rates, and wherein a thickness of the damage suppressing layer is equal to or smaller than 200 nm.