Heteroepitaxial alpha-Ga2O3 MOSFETs with a 2.3 kV breakdown voltage grown by halide vapor-phase epitaxy

Abstract

Here, we report on heteroepitaxial alpha-Ga2O3 MOSFETs with a breakdown voltage (BV) of 2.3 kV at a specific on-resistance of 335 m omega cm(2). High-quality alpha-Ga2O3 layers were grown on a sapphire substrate via halide vapor-phase epitaxy (HVPE). A stack of Ti/Al/Ni/Au was used for the S/D electrode, exhibiting significantly reduced contact resistance as compared with a conventional Ti/Au stack. Consequently, the record BV and mobility of 20.4 cm(2) V-1 s(-1) were achieved. Moreover, a consistent critical field of 1 MV cm(-1) was obtained for variable L-GD. Our results are superior to recently reported heteroepitaxial alpha-/beta-Ga2O3 MOSFETs, which is promising toward HVPE alpha-Ga2O3 based power devices. (C) 2022 The Japan Society of Applied Physics