1 kV Vertical $\beta$-Ga2O3 Heterojunction Barrier Schottky Diode with Hybrid Unipolar and Bipolar Operation

In this work, a vertical $\beta$-Ga2O3 heterojunction barrier Schottky diode (HJBS) with hybrid unipolar and bipolar operation has been demonstrated by implementing p-type NiO. HJBS exhibits a low on-state voltage similar to the traditional Schottky barrier diode, and a low reverse leakage current close to NiO/$\beta$-Ga2O3 heterojunction diode (HJD). The current conduction mode shifts from unipolar mode with high conduction resistance to bipolar mode with low conduction resistance when the forward voltage exceeds the turn-on voltage of the HJD. In addition, the hybrid operating mode of HJBS was further elaborated through temperature dependent electrical characteristics. These results preliminarily prove the existence of bipolar behavior in $\beta$-Ga2O3 HJBS.