Patent ID: 8841683

Claim:
A semiconductor rectifier device comprising: a semiconductor substrate of a first conductive type of a wide gap semiconductor; a semiconductor layer of the first conductive type of the wide gap semiconductor formed on an upper surface of the semiconductor substrate, wherein an impurity concentration of the semiconductor layer is between 1E+14 atoms/cm 3 and 5E+16 atoms/cm 3 inclusive, and a thickness thereof is 8 μm or more; a first semiconductor region of the first conductive type of the wide gap semiconductor formed at the semiconductor layer surface; a plurality of second semiconductor regions of a second conductive type of the wide gap semiconductor formed as sandwiched by the first semiconductor regions, wherein a width of each of the second semiconductor regions is 15 μm or more; a further semiconductor region of the second conductive type of the wide gap semiconductor formed outside of the second semiconductor regions, the further semiconductor region having a width wider than the second semiconductor regions; an insulating film covering a part of the further semiconductor region; a first electrode formed in an opening of the insulating film, the first electrode being formed on an entire surface of the first and second semiconductor regions, the first electrode being formed on only a part of a surface of the further semiconductor region; and a second electrode formed on a lower surface of the semiconductor substrate.