High Performance $\beta$-Ga2O3 Vertical Rectifier With Double Step Structure Termination Using Thermally Oxided TiOx Dielectrics

A high performance (001) $\beta$ -Ga 2 O 3 vertical Schottky barrier diode (SBD) with double step structure termination using thermally oxided TiO x dielectrics is reported in this paper. The novel termination effectively reduces the leakage current caused by the high electric field at the edge of Schottky junction. By using the double step structure TiO x layers, the breakdown voltage $(V_{\text{br}})$ increases from 460V to 950V, and the specific on-resistance $(R_{\text{on},\text{sp}})$ just increases from 2.7 $\mathrm{m}\Omega\cdot \text{cm}^{3}$ to 2.8 $\mathrm{m}\Omega\cdot \text{cm}^{2}$ . The fabricated device shows a high power figure of merit (PFOM) of 329 MW/cm2. These results show a new way to improve the breakdown characteristics of $\beta$ -Ga 2 O 3 SBD.