Fabrication of Ampere-Class $p$-Cu2O/$n-\beta$-Ga2O3 Trench Heterojunction Barrier Schottky Diodes and Double-Pulse Evaluation

Abstract

Ampere-class $\beta$-Ga2O3 trench heterojunction barrier Schottky diodes (THJBSs) were successfully developed for the first time. In fabrication, a lift-off process replacing an etching process was used to form $p$-type Cu2O that works as a heterojunction component, which contributed to the realization of ampere-class devices. Experimental results with the fabricated $\beta$-Ga2O3 THJBSs indicate a turn-on voltage of 1.1 V, maximum current of 3.5 A, and specific on-resistance of $21 \mathrm{m}\Omega\cdot \text{cm}^{2}$ in forward characteristics. The breakdown voltage was −986 V with leakage current of $1.3\times 10^{-3}\ \mathrm{A}/\text{cm}^{2}$ in reverse characteristics. In double-pulse measurements, the devices exhibited fast and low-loss switching behavior similar to general Schottky barrier diodes (SBDs), suggesting that the device operated with only majority carriers. In addition, from a high-temperature reverse-bias (HTRB) test, steady reverse current without breakdown was confirmed under the stress for 428 h. These results confirm that the ampere-class $\beta$-Ga2O3 THJBSs are suitable for applications requiring fast switching, low loss, and high reliability.