Vertical fin Ga2O3 power field-effect transistors with on/off ratio >109

Abstract

Recently, Ga2O3 has become an attractive material for both power electronic and optoelectronic device applications since large-size electronic-grade Ga2O3 substrates can be readily produced by melt-grown methods. Furthermore, high quality epitaxy and n-type doping schemes have been demonstrated [1, 2]. Due to its ultra-wide band gap (∼4.5–4.9 eV), Ga2O3 is estimated to have a critical breakdown field >6 MV/cm, comparing favorably with ∼3 MV/cm in SiC and ∼4 MV/cm in GaN. This allows devices capable of handling large switching voltages. Devices such as lateral channel MOSFETs, MESFETs [3], MISFETs [4], nano-membrane FETs [5] and lateral FinFETs [6], vertical Schottky Barrier Diodes (SBDs) [7, 8], and deep-UV solar-blind photodetectors [9] have all been demonstrated using Ga2O3. Here, we report the first Ga2O3 vertical power transistors with a breakdown voltage (BV) of 185 V.