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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.

The Pt/β-Ga2O3 Schottky barrier diode and its temperature-dependent current-voltage characteristics were investigated for power device application. The edge-defined film-fed growth (EFG) technique was utilized to grow the (100)-oriented β-Ga2O3 single crystal substrate that shows good crystal quality characterized by X-ray diffraction and high resolution transmission electron microscope. Ohmic and Schottky electrodes were fabricated by depositing Ti and Pt metals on the two surfaces, respectively. Through the current-voltage (I-V) measurement under different temperature and the thermionic emission modeling, the fabricated Pt/β-Ga2O3 Schottky diode was found to show good performances at room temperature, including rectification ratio of 1010, ideality factor (n) of 1.1, Schottky barrier height (ΦB) of 1.39 eV, threshold voltage (Vbi) of 1.07 V, ON-resistance (RON) of 12.5 mΩ·cm2, forward current density at 2 V (J@2V) of 56 A/cm2, and saturation current density (J0) of 2 × 10−16 A/cm2. The effective donor c...