Silicon carbide semiconductor device for pinching off leakage current

A silicon carbide semiconductor device, comprising:

• a SiC substrate of a first conductivity type;
• a drift layer of the first conductivity type disposed on the substrate;
• a plurality of first doping regions of a second conductivity type formed near a surface of the drift layer, each of the first doping regions being spaced from each other;
• a plurality of second doping regions of the first conductivity type formed near the surface of the drift layer, each sandwiched between two of the first doping regions;
• a first metal layer disposed on the surface of the drift layer, the first metal layer being in direct contact with the first doping regions and forming an Ohmic contact with the second doped region;
• and
• wherein the drift layer has a first doping concentration of the first conductivity type, each of the second doping regions has a second doping concentration of the first conductivity type, which is equal or higher than the first doping concentration;
• wherein each of the first doping regions has a first depth (D1), each of the second doping regions has a second depth (D2) which is smaller than the first depth (D1);
• and
• wherein each of the first doping regions has a third doping concentration of the second conductivity type and a first spacing (S1) is provided between the first doping regions, wherein the first depth (D1) of the first doping regions, the third doping concentration of the first doping regions and the first doping concentration of the drift layer are configured such that a region of the drift layer between the first doping regions is completely depleted to pinch off a leakage current when a reverse bias is applied to the silicon carbide semiconductor device,
• wherein the first depth is on an order of magnitude of 1 μm, the third concentration is on an order of magnitude of 1E18 cm{circumflex over ( )}−3, and the first doping concentration is on an order of magnitude of 1E16 cm{circumflex over ( )}−3.