Patent ID: 7851882

Claim:
A silicon carbide semiconductor device having a junction barrier schottky diode comprising: a substrate made of first conductive type silicon carbide, the substrate having a main surface and a rear surface; a drift layer made of the first conductive type silicon carbide disposed on the main surface of the substrate, an impurity concentration of the drift layer being lower than an impurity concentration of the substrate, wherein the drift layer includes a cell region; an insulating film having an opening portion disposed on the drift layer, the opening portion being disposed in the cell region; a plurality of second conductive type layers disposed in the cell region of the drift layer; and a schottky barrier diode having a schottky electrode and an ohmic electrode, the schottky electrode being disposed on the drift layer in the opening portion of the cell region and the ohmic electrode being disposed on the rear surface of the substrate, wherein the schottky electrode and a surface of the drift layer provide a schottky contact, the plurality of second conductive type layers are separated from each other and contact the schottky electrode, the plurality of second conductive type layers and the drift layer provides a PN diode, and a size and an impurity concentration of the plurality of second conductive type layers and a size and an impurity concentration of a portion of the drift layer sandwiched between the plurality of second conductive type layers are determined so that a charge quantity of the plurality of second conductive type layers is equal to a charge quantity of the portion.