Vertical Schottky barrier diodes based on a bulk $\beta$ -Ga2O3 substrate with high switching performance

Abstract

In this study, we developed $\beta$ -Ga 2 O 3 -based vertical Schottky barrier diodes (SBDs) and investigated their switching performance. The devices were fabricated by epitaxy of an $\mathrm{n}^{-}-\beta$ -Ga 2 O 3 drift layer on an n-type (001) $\beta$ -Ga 2 O 3 substrate and using Pt as the Schottky metal. The SBDs showed an excellent Schottky contact with a low ideality factor of ~1.02 and a high on/off current ratio $(\mathrm{I}_{\mathrm{ON}}/\mathrm{I}_{\mathrm{OFF}})$ of over 6 orders of magnitude at −300 V. The reverse recovery characterization of the $\beta$ -Ga 2 O 3 SBD was performed and compared with a commercial Si fast-recovery diode (FRD). When switching from an on-state current of 350 mA to a reverse-blocking voltage of −100 V, the vertical $\beta$ -Ga 2 O 3 SBD exhibits fast reverse recovery with a reverse recovery time $(\mathrm{t}_{\mathrm{rr}})$ of ~14.1 ns and reverse recovery charge $(\mathrm{Q}_{\mathrm{rr}})$ of ~ 0.34 nC, outperforming the Si FRD of similar ratings. In addition, the Si FRD showed significantly increased $\mathrm{t}_{\mathrm{rr}}$ and $\mathrm{Q}_{\mathrm{rr}}$ when the on-state current was set higher, while the $\beta$ -Ga 2 O 3 SBDs exhibited similar behavior when switched-off from various level of on-state current. The results demonstrate the great potential of $\beta$ -Ga 2 O 3 SBDs for high-speed switching applications.