Patent ID: 8912622

Claim:
A semiconductor device comprising: a first-conductivity-type semiconductor substrate; a first first-conductivity-type semiconductor layer provided on the semiconductor substrate and having a lower first-conductivity-type impurity concentration than the semiconductor substrate; a second first-conductivity-type semiconductor layer provided on the first first-conductivity-type semiconductor layer and having a higher first-conductivity-type impurity concentration than the first first-conductivity-type semiconductor layer; a Schottky metal provided on the second first-conductivity-type semiconductor layer and partly contacting with the first first-conductivity-type semiconductor layer; a second-conductivity-type bottom layer provided in the first first-conductivity-type semiconductor layer and connected to the Schottky metal; and a cathode electrode connected to the semiconductor substrate; wherein the first-conductivity-type impurity concentration of the second first-conductivity-type semiconductor layer gradually increases from an end on an opposite side from the semiconductor substrate toward an end on the semiconductor substrate side, and then gradually decreases.