Suppression of Leakage Current of Ni/Au Schottky Barrier Diode Fabricated on AlGaN/GaN Heterostructure by Oxidation

Abstract

We have proposed and fabricated a lateral GaN Schottky barrier diode (SBD) that increases the breakdown voltage and decreases the leakage current by the oxidation of a Ni/Au Schottky contact. After an oxidation, the anode current was increased under a high anode bias, whereas the turn-on voltage was slightly increased. The leakage current was considerably decreased to less than 1 nA after the oxidations of 5 and 10 min. A high breakdown voltage of 750 V was measured in the proposed GaN SBD when multiple floating metal rings (FMRs) were used for edge termination and oxidation was employed. We have also measured the reverse recovery waveforms at room temperature and 125 °C and the fabricated GaN SBDs show very fast reverse recovery characteristics.