1.92 kV/5 A β-Ga2O3 Schottky Barrier Diodes With Room-Temperature Sputtered Al2O3 Field Plate

Abstract

This work reports a significant enhancement in the performance of $\beta $ -Ga2O3 Schottky barrier diodes (SBDs) by employing a room-temperature sputtered Al2O3 field plate (FP). The fabricated sputtering FP-SBD achieves a high reverse breakdown voltage ( ${V}_{\text {br}}\text {)}$ of 1.92 kV, a specific on-resistance ( ${R}_{\textsc{on,} \text{sp}}\text {)}$ of 7.1 m $\Omega \cdot $ cm2, and a forward current ( ${I}_{\text {F}}\text {)}$ of 5 A, yielding a high-power figure-of-merit (PFOM) of 0.52 GW/cm2 for large-area (>1 $\mathrm{mm}^{{2}}\text {)}$ devices. Compared to atomic layer deposition (ALD) counterparts, the sputtering FP-SBD demonstrates a 47.69% improvement in ${V}_{\text {br}}$ with only a marginal 13.9% reduction in ${I}_{\text {F}}$ at 2 V. This substantial advancement in reverse blocking capability is attributed to the minimized thermal budget and interfacial sheet charges. X-ray photoelectron spectroscopy (XPS) analyses further reveal that the sputtered interface possesses a lower proportion of oxygen vacancies. The sputtering FP-SBD exhibits a fast reverse recovery time of 8.54 ns and a low reverse recovery charge of 10.49 nC (at di/dt = 510 A/ $\mu $ s) with ${V}_{\text {br}}$ of 100 V, maintaining excellent rectification characteristics. These results underscore the efficacy of room-temperature sputtering as a low-thermal-budget process for realizing high-performance $\beta $ -Ga2O3 power electronics.