Depletion-Mode -Ga₂O₃ MOSFETs Grown by Nonvacuum, Cost-Effective Mist-CVD Method on Fe-Doped GaN Substrates

In this work, beta-Ga2O3 MOSFETs grown by nonvacuum, cost-effective mist chemical vapor deposition (mist-CVD) method on Fe-doped GaN substrates were demonstrated for the first time. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements identify the pure beta-Ga2O3 phase and the heteroepitaxial relationship with (201) beta-Ga2O3 parallel to (0002) GaN. MOSFETs based on beta-Ga2O3 thin films with source-drain spacings (L-gd) of 14 and 25 mu m were fabricated and characterized. The destructive breakdown voltages (V-BR) were measured to be 836 and 1420 V, respectively. The ON-OFF ratio of the corresponding MOSFETs was about five orders of magnitude. These results suggest the great application potential of the nonvacuum and cost-effective mist-CVD epitaxial growth method in beta-Ga2O3 MOSFETs, which will greatly decrease the device cost.