SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

摘要

A semiconductor device includes first and second second-conductivity-type region groups containing multiple second-conductivity-type regions that are disposed on a first silicon carbide semiconductor layer of a first conductivity type, arrayed in parallel following one direction with a space between each other, and first and second electrodes disposed on the first silicon carbide semiconductor layer and forming a Schottky junction with the first silicon carbide semiconductor layer. The first electrode covers a position where a distance from adjacent first and second second-conductivity-type regions included in a first second-conductivity-type region group, and a distance from a third second-conductivity-type region included in a second second-conductivity-type region group and adjacent to the first and second second-conductivity-type regions, are equal. 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.

主权项

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 first electrode that is disposed on the first silicon carbide semiconductor layer and forms a Schottky junction with the first silicon carbide semiconductor layer; a second electrode that is disposed on the first silicon carbide semiconductor layer and is electrically connected with the first electrode, 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
a first second-conductivity-type region group containing a plurality of second-conductivity-type regions that are arrayed following one direction with a space between each other, when viewed from a direction perpendicular to the principal surface of the semiconductor substrate, anda second second-conductivity-type region group containing a plurality of second-conductivity-type regions that are arrayed following the one direction with the space between each other, when viewed from the direction perpendicular to the principal surface of the semiconductor substrate; the second second-conductivity-type region group is disposed in parallel with the first second-conductivity-type region group; 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 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.