Patent ID: 7078781

Claim:
A high-breakdown-voltage semiconductor device comprising: a high-resistance semiconductor layer of a first conductivity type having a first main surface and a second main surface, a plurality of first trenches being formed on the first main surface of the high-resistance semiconductor layer in a longitudinal plane shape and arranged in parallel with each other; a first electrode formed on each of surface regions of the first main surface of the high-resistance semiconductor layer to form a Schottky junction therewith, each of the surface regions being sandwiched between adjacent trenches of the plurality of first trenches; a first semiconductor region of a second conductivity type continuously disposed in a sidewall and a bottom portion of each of the plurality of first trenches; a sidewall insulating film disposed on the first semiconductor region of the sidewall of each of the plurality of first trenches; a second semiconductor region of the second conductivity type disposed in a surface region of the first semiconductor region of the bottom portion of each of the plurality of first trenches and having an impurity concentration higher than that of the first semiconductor region; a third semiconductor region of the first conductivity type disposed on the second main surface of the high-resistance semiconductor layer and having an impurity concentration higher than that of the high-resistance semiconductor layer; a control electrode filling each of the plurality of first trenches in contact with the second semiconductor region and connected to the first electrode; and a second electrode formed on the third semiconductor regions, wherein the high-resistance semiconductor layer further comprises second trenches communicating with the plurality of first trenches at both ends of longitudinal sides thereof, and each of the surface regions in which the Schottky junction is formed is surrounded by the plurality of first trenches and the second trenches.