Design of Enhancement Mode β-Ga₂O₃ Vertical Current Aperture MOSFETs With a Trench Gate

In this article, enhancement-mode (E-mode) operation is achieved by employing a trench gate on the $\beta $ -Ga2O3 current aperture vertical MOSFETs via Sentaurus TCAD simulation. The performance of the trench gate $\beta $ -Ga2O3 MOSFETs was investigated with different structure parameters, such as trench gate depth, channel doping concentration, and drift layer doping concentration and thickness. The transistor with a trench gate recess (Gr) of 130 nm obtained a high on/off current ratio of $10^{8}$ , an on-current density of 65 A/cm2, a low specific on-resistance ( $\text{R}_{\mathrm {on,sp}}$ ) of 42.5 $\text{m}\Omega \cdot $ cm2, and a breakdown voltage (BV) of 488 V for an E-mode operation. With the thickness of the drift layer increasing to $9.2 \mu \text{m}$ , BV is improved to 721 V, $\text{R}_{\mathrm {on,sp}}$ keeps a low value of 43.5 $\text{m}\Omega \cdot $ cm2 due to the trench gate structure, and the transfer characteristic maintains the same. The thermal characteristics of the proposed MOSFET were studied and the device stability with high temperature was analyzed. The transistor with Gr = 130 nm can keep working in E-mode operation at T = 500 K. The performance of the transistor exhibits its great potential as a high-voltage switch device for power electronic applications.