Unidirectional AlGaN/GaN-on-Si HFETs with reverse blocking drain

We have developed a novel unidirectional AlGaN/GaN-on-Si heterojunction field-effect transistor (HFET) with reverse blocking drain. A recessed Schottky contact was incorporated into a conventional ohmic drain electrode to prevent the undesired reverse current flow while reducing the turn-on voltage in forward current characteristics. The combination of recessed Schottky and ohmic electrodes significantly reduced the turn-on voltage in comparison with a conventional Schottky drain. A turn-on voltage of 0.4 V, an off-state forward breakdown voltage of 615 V, and a reverse blocking drain voltage of −685 V were achieved for the gate-to-drain distance of 12 µm.