Abstract: A silicon carbide semiconductor device includes trenches formed in a lattice shape on the surface of a silicon carbide substrate on which a semiconductor layer is formed, and gate electrodes formed inside of the trenches via a gate insulating film. The depth of the trenches is smaller in a portion where the trenches are crossingly formed than in a portion where the trenches are formed in parallel to each other. Consequently, the silicon carbide semiconductor device is obtained that increases a withstand voltage between the gate electrodes and corresponding drain electrodes on the semiconductor device rear surface to prevent dielectric breakdown and, at the same time, has a large area of the gate electrodes, high channel density per unit area, and low ON resistance.

Abstract: A silicon-carbide semiconductor device that relaxes field intensity in a gate insulating film, and that has a low ON-resistance. The silicon-carbide semiconductor device includes: an n-type silicon-carbide substrate; a drift layer formed on a topside of the n-type silicon-carbide substrate; a trench formed in the drift layer and that includes therein a gate insulating film and a gate electrode; a p-type high-concentration well region formed parallel to the trench with a spacing therefrom and that has a depth larger than that of the trench; and a p-type body region formed to have a depth that gradually increases when nearing from a position upward from the bottom end of the trench by approximately the thickness of the gate insulating film at the bottom of the trench toward the lower end of the p-type high-concentration well region.

Abstract: In a JBS diode using a wide band gap semiconductor, the wide band gap semiconductor has a large built-in voltage, which sometimes causes difficulties for the pn diode portion to turn on, resulting in a problem that resistance to surge currents is not sufficiently ensured. In order to solve this problem, in the wide-band-gap JBS diode, a pn junction of the pn diode is formed away from the Schottky electrode, and well regions are formed so as to have a width narrowed at a portion away from the Schottky electrode.