SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME, POWER CONVERSION DEVICE, THREE-PHASE MOTOR SYSTEM, AUTOMOBILE, AND RAILWAY CARRIAGE

摘要

The purpose of the present invention is to provide a power semiconductor device exhibiting high performance and high reliability. This semiconductor device has: a first electroconductive type semiconductor substrate; a drain electrode formed on the rear surface side of the semiconductor substrate; a first electroconductive type drift layer formed on the front surface side of the semiconductor substrate; a first electroconductive type source region; a first electroconductive type electric current diffusion layer; a second electroconductive type body layer abutting the source region and the electric current diffusion layer, the second electroconductive type being opposite the first electroconductive type; a trench extending to the source region, the body layer, and the electric current diffusion layer, the trench being shallower than the body layer, and the bottom surface of the trench abutting the body layer; a first electroconductive type high-concentration JFET layer formed to a position shallower than the interface between the electric current diffusion layer and the body layer, the JFET layer electrically connecting the drift layer and the electric current diffusion layer and having a higher impurity concentration than that of the drift layer; a gate insulation film formed on the inside wall of the trench; and a gate electrode formed on the gate insulation film.