Semiconductor device including vertical MOSFET and Schottky barrier diode

A semiconductor device, comprising:

• a semiconductor substrate of a first conductivity type;
• a first semiconductor layer of the first conductivity type provided on a front surface of the semiconductor substrate, wherein the first semiconductor layer has an impurity concentration that is lower than an impurity concentration of the semiconductor substrate;
• a second semiconductor layer of a second conductivity type provided on a side of the first semiconductor layer, that is opposite to a side of the first semiconductor layer, that faces the semiconductor substrate;
• a first semiconductor region of the first conductivity type selectively provided in the second semiconductor layer, wherein the first semiconductor region has an impurity concentration that is higher than the impurity concentration of the first semiconductor layer;
• a plurality of second semiconductor regions of the second conductivity type provided in the first semiconductor layer;
• a plurality of third semiconductor regions of the second conductivity type provided from a surface of the first semiconductor layer and having bottoms in contact with the plurality of second semiconductor regions;
• a first trench and a second trench that penetrate the first semiconductor region and the second semiconductor layer and reach the first semiconductor layer, respective bottoms of the first trench and the second trench being in contact with the plurality of second semiconductor regions, respectively;
• a gate electrode provided in the first trench via a gate insulating film;
• and
• a Schottky electrode provided in the second trench, wherein
• the second trench has sidewalls that are apart from the plurality of second semiconductor regions and the plurality of third semiconductor regions, in a region between an active region through which a current flows during an on-state and an edge region that surrounds a periphery of the active region and sustains a breakdown voltage.