Patent ID: 8581359

Claim:
Schottky barrier diode comprising: an electrically conductive support substrate having a front substrate surface; a gallium nitride underlying layer deposited on said front substrate surface of said electrically conductive support substrate; a gallium nitride layer deposited on said gallium nitride underlying layer, said gallium nitride layer having a front surface opposite to said gallium nitride underlying layer; an insulation layer deposited on said gallium nitride layer at said front surface and having an opening; a Schottky electrode deposited in said opening in contact with said gallium nitride layer; and a field plate electrode connected to said Schottky electrode and also overlapping said insulation layer, wherein said insulation layer has a round opening where said field plate electrode is formed and said field plate electrode overlaps said insulation layer in a cross section that traverses a center of said Schottky electrode that is round in geometry, wherein said electrically conductive support substrate and said gallium nitride underlying layer are connected to each other by bonding and together make ohmic contact, wherein said gallium nitride layer has a region in contact with said Schottky electrode, said region having a dislocation density of at most 1×10 8 cm −2 , and wherein said insulation layer is formed of silicon nitride film and contains hydrogen having a concentration of less than 3.8×10 22 cm −3 .