Patent attributes
A semiconductor device including a semiconductor substrate of a first conductivity type, a first semiconductor layer of the first conductivity type, provided at a front surface of the semiconductor substrate and having an impurity concentration lower than that of the semiconductor substrate, a second semiconductor layer of a second conductivity type, selectively provided on the first semiconductor layer, a first semiconductor region of the first conductivity type, selectively provided in the second semiconductor layer and having an impurity concentration higher than that of the semiconductor substrate, a trench penetrating the first semiconductor region and the second semiconductor layer, to reach the first semiconductor layer, and a gate electrode provided in the trench, via a gate insulating film. The trench has a sidewall that includes a terrace portion, surface roughness of the terrace portion being at most 0.1 nm.
