Optimization for a High-Voltage Recessed-Gate $\beta-\text{Ga}_{2} \mathrm{O}_{3}$ MOSFET by Gate and Drain Field Plate Technology

In this paper, a recessed-gate ${\beta}-{\text{Ga}_2\mathrm{O}_{3}}$ MOSFET is investigated by TCAD. Enhanced mode is obtained by etching the channel layer to be 40 nm. High breakdown voltage and low specific on-resistance $({R}_{\text{on.sp}})$ is obtained by optimizing the field plate length and SiO2 thickness for the gate and drain field plates, as well as the doping concentration of the channel layer. Simulation results show that when the gate and drain field plates are 4 μm and 2 μm with SiO2 thickness being 500 nm, the device obtains a BV of 4256 V and ${R}_{\text{on,sp=23.3m}\Omega\cdot \text{cm}^{2}}$, showing a high Baliga's Figure of merit of $777.4 \text{MW/cm}^{2}$.