Simulation Study on Electrical Characteristics of NiO/β-Ga2O3 Heterojunction Enhancement Mode HJ-FinFET

In this paper, a novel enhancement-mode β-Ga2O3-based FinFET structure with a gate formed by the NiO/β-Ga2O3 heterojunction named HJ-FinFET has been proposed, and the excellent performance of the device has also been demonstrated. The primary operational mechanism of this structure involves integrating p-type NiO on both sides of the fin-shaped channel, which forms p-n junctions with β-Ga2O3. The depletion regions thus generated are utilized to establish electron channels, enabling enhancement-mode operation. The reverse p-NiO/n-Ga2O3 heterojunction diode is integrated to reduce the reverse free-wheeling loss. Compared with the conventional devices, the threshold voltage of the HJ-FinFET is greatly improved, and normally off operation is realized, showing a positive threshold voltage of 2.14 V. Meanwhile, the simulated breakdown voltage of the HJ-FinFET reaches 2.65 kV with specific on-resistance (Ron,sp) of 2.48 mΩ·cm2 and the power figure of merit (PFOM = BV2/Ron,sp) reaches 2840 MW/cm2, respectively. In addition, the influence of the doping concentration of the heterojunction layer constituting the gate, the doping concentration of the drift layer, and the channel width on the electrical characteristics of the devices were focused on. This structure provides a feasible idea for high-performance β-Ga2O3-based FinFET.