Patent ID: 9577044
Date: 2017-02-21
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a semiconductor substrate of a first conductivity type, having a principal surface; a first silicon carbide semiconductor layer of the first conductivity type, disposed on the principal surface of the semiconductor substrate; a plurality of second-conductivity-type region groups each containing a plurality of second-conductivity-type regions, disposed in the first silicon carbide semiconductor layer; a plurality of first electrodes, each of which is disposed on the first silicon carbide semiconductor layer and forms a Schottky junction with the first silicon carbide semiconductor layer, the plurality of first electrodes including a first electrode; a second electrode that is disposed on the first silicon carbide semiconductor layer and is electrically connected with the plurality of first electrodes, and that forms a Schottky junction with the first silicon carbide semiconductor layer; and a third electrode disposed on a rear surface of the semiconductor substrate, wherein: the plurality of second-conductivity-type region groups include: the second second-conductivity-type region group is disposed in parallel with the first second-conductivity-type region group in a second direction crossing the first direction when viewed from the normal direction, the second electrode covers a first portion which is at least a portion of the first silicon carbide semiconductor layer between two of the second-conductivity-type regions that are adjacent and included in the first second-conductivity-type region group and the second second-conductivity-type region group, the portion being in contact with each of the two adjacent second-conductivity-type regions, one of the two adjacent second-conductivity-type regions included in the first second-conductivity-type region group is defined as a first second-conductivity-type region and the other of the two adjacent second-conductivity-type regions included in the first second-conductivity-type region group is defined as a second second-conductivity-type region, the second-conductivity-type region included in the second second-conductivity-type region group and adjacent to the first second-conductivity-type region and the second second-conductivity-type region is defined as a third second-conductivity-type region, the first electrode of the plurality of first electrodes covers, of the first silicon carbide semiconductor layer in a region surrounded by the first second-conductivity-type region, the second second-conductivity-type region, and the third second-conductivity-type region, a position where a distance from the first second-conductivity-type region, a distance from the second second-conductivity-type region, and a distance from the third second-conductivity-type region are mutually equal, and a Schottky barrier between the first electrode and the first silicon carbide semiconductor layer is larger than a Schottky barrier between the second electrode and the first silicon carbide semiconductor layer.