Hysteresis-free and μs-switching of D/E-modes Ga2O3 hetero-junction FETs with the BV2/Ron,sp of 0.74/0.28 GW/cm2

Abstract

In this Letter, we report on establishing high performance hysteresis-free and μs-switching depletion/enhancement-mode (D/E-mode) β-Ga2O3 heterojunction (HJ) field effect transistors (FETs) with the state-of-art power figure-of-merit (P-FOM). By optimizing the p-NiOx/n-Ga2O3 interface and n-Ga2O3 recess technology, a positive threshold voltage (VT) as well as a low subthreshold slope can be substantially achieved. The trade-off between the on-resistance (Ron,sp) and breakdown voltage (BV) is improved by incorporation of T-shaped NiOx, resulting in the Ron,sp of 6.24/13.75 mΩ cm2 and the breakdown voltage (BV) of 2145/1977 V for D/E-mode devices and yielding the P-FOM = BV2/Ron,sp to be 0.74/0.28 GW/cm2. To the best of all the authors' knowledge, those P-FOMs are the highest ones among all published lateral Ga2O3 FETs. Benefited from the high-quality interface, a negligible hysteresis of 4 mV and μs-switching can be essentially achieved, showing the great promise of Ga2O3 HJ-FETs for future high-power, high-efficiency, and high-speed power electronics.