Gate-mesa trench enables enhanced β-Ga2O3 MOSFET with higher power figure of merit

Abstract

In this article, a gate-mesa trench (GMT) β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) device with enhanced performance and breakdown voltage improvement is proposed. Compared with the gate-field plate trench (GFPT), the breakdown voltage and power figure of merit (PFOM) of the GMT device are 2566 V and 680.53 MW cm−2 respectively, which are 1.56 times and 2.25 times higher than those of the GFPT, demonstrating excellent device performance. When the etch depth is 200 nm, the specific on-resistance of the GFPT and the GMT is 8.84 mΩ cm−2 and 9.76 mΩ cm−2, respectively, with the peak transconductance of the GFPT being 61.56 mS mm−1 when the epitaxial layer doping concentration is 3 × 1017 cm-3, which is 1.22 times that of the GMT. The high dielectric constant HfO2 dielectric can significantly improve the PFOM of the device, while the gate oxide Al2O3 drifts the threshold voltage to the right. This article presents a novel approach for designing high-performance enhanced β-Ga2O3 MOSFETs.