Novel Vertical Fin-Based NiO/β-Ga2O3 Heterojunction Field-Effect Transistor with a Low Ron,sp

Abstract

In this paper, a novel vertical fin-based NiO/β-Ga2O3 heterojunction field-effect transistor (Fin-HJFET) is proposed and studied by TCAD. Theoretically high conduction band offset () enables Ga2O3 Fin-HJFET to produce electron confinement effect at certain gate bias voltage. According to the simulation results, this effect makes Ga2O3 Fin-HJFET can not only form surface-conducting fin channels that are not available in conventional fin-based junction field-effect transistor (Fin-JFET) but also have a stronger electron accumulation capability than Ga2O3 vertical FinFET due to the deep potential well, which leads to a lower specific on-resistance (). In addition, Ga2O3 Fin-HJFET inherits the advantages of Ga2O3 FinFET as a vertical normally-off device and has a higher breakdown voltage compared to FinFET without field plates due to the protection of the highly doped NiO layer. Particularly, Fin-HJFET with different heterojunction band alignments are also considered and discussed. At last, the parameter influence and future optimization space of this highly promising device are explored, providing guidance for actual device fabrication and future device improvement.