Low turn-on voltage and improved interface properties of β-Ga2O3 Schottky barrier diodes with NH3 plasma treatment

In this work, we investigate the effect of the NH3 plasma treatment on the interface properties and electrical characteristics of β-gallium oxide (β-Ga2O3) Schottky barrier diodes (SBDs). The interfacial chemical modifications reduce the apparent interface trap density and are accompanied by a decrease in the turn-on voltage from 0.96 to 0.73 V. The x-ray photoelectron spectroscopy results reveal that the nitrogen is introduced into the β-Ga2O3 surface to form Ga–N bonds, while the Ga-suboxide and adsorbed oxygen are simultaneously reduced during NH3 plasma treatment. In addition, following the treatment, the dominant reverse leakage mechanism of the β-Ga2O3 SBD shifts from trap-assisted tunneling to thermionic field emission, while the measured breakdown voltage increases by 18%. These results demonstrate that NH3 plasma treatment provides an effective interface engineering strategy for enhancing the performance of β-Ga2O3 SBDs.