Power semiconductor device comprising a wide bandgap substrate

A power device comprising:

• a substrate comprising a p-doped SiC material, the substrate comprising a first surface and a second surface opposite the first surface;
• a high voltage heterojunction transistor formed over the first surface of the substrate, the high voltage heterojunction transistor comprising:
• a III-nitride semiconductor region comprising a heterojunction formed between a GaN layer and an AlGaN layer;
• a drain terminal operatively connected to the III-nitride semiconductor region;
• a source terminal laterally spaced from the drain terminal and operatively connected to the III-nitride semiconductor region;
• and
• a gate terminal positioned over the III-nitride semiconductor region, the gate terminal being formed between the drain terminal and the source terminal;
• a high voltage diode comprising:
• a first p-doped region with a first doping density, the first p-doped region associated with the substrate,
• a second p-doped region with a second doping density, wherein the second doping density is less than the first doping density, the second p-doped region positioned between the first p-doped region and the first surface and forming a drift region for the high voltage diode such that at least part of the drift region is directly under and in physical contact with the high voltage heterojunction transistor;
• and
• an anode terminal operatively connected to the second surface of the substrate and to the source terminal;
• and
• a cathode terminal operatively connected to the first surface of the substrate and to the drain terminal.