1.2kV/2.9mΩ.cm2 Vertical NiO/β-Ga2 O3 Heterojunction Diodes with High Switching Performance

In this study, we developed novel vertical $\mathrm{N}\mathrm{i}\mathrm{O}/\beta-\mathrm{G}\mathrm{a}_{2}\mathrm{O}_{3}$ heterojunction power diodes and investigated both their static and switching performances. By sputtering p-NiO onto the $\mathrm{n}^{-}-\beta-\mathrm{G}\mathrm{a}_{2}\mathrm{O}_{3}$ drift layer, a bipolar operation mode with excellent static performances was achieved including a high breakdown voltage $(V_{B)}$ of 1.2 kV and a low diffusion specific on-resistance $(R_{on,sp})$ of 2.9 $\mathrm{m}\Omega\cdot \mathrm{c}\mathrm{m}^{2}$. To further evaluate the switching performance of the $\mathrm{N}\mathrm{i}\mathrm{O}/\beta-\mathrm{G}\mathrm{a}_{2}\mathrm{O}_{3}$ heterojunction diodes, a double-pulse test was performed. When switching from a forward current of up to 1 A to a reverse-blocking voltage of -55 V, the device exhibited fast reverse recovery with a reverse recovery time $(t_{rr})$ of $\sim 60$ ns and reverse recovery charge $(Q_{rr})$ of $\sim 1.97\mathrm{n}\mathrm{C}$, which is outperforming the reference commercial Si fast-recovery diode (FRD). These results demonstrate a great promise of $\mathrm{N}\mathrm{i}\mathrm{O}/\beta-\mathrm{G}\mathrm{a}_{2}\mathrm{O}_{3}$ heterojunction diodes for further high-efficiency power switching applications.