A Novel Recessed p-NiO/TiN Composite Anode AlGaN/GaN Schottky Diodes

To improve the breakdown voltage (BV) of AlGaN/GaN heterojunction Schottky barrier diodes while maintaining a low turn-on voltage (VTH), this work proposes an AlGaN/GaN Schottky diode with a composite anode structure composed of p-type NiO and TiN. In this structure, the p-NiO anode can deplete the two-dimensional electron gas (2DEG) under reverse bias, effectively achieving low leakage current (IR) of the device; the TiN anode ensures a low VTH by virtue of its low work function. In addition, under reverse bias conditions, the recessed p-NiO structure can block the lateral electric field in the AlGaN barrier layer, alleviate the electric field crowding beneath the TiN anode, and thereby enhance the BV of the device.