Depletion-Mode β -Ga 2 O 3 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 ($\bar {2}01$) $\beta $ -Ga2O3 $\|$ (0002) GaN. MOSFETs based on $\beta $ -Ga2O3 thin films with source–drain spacings (${L}_{\text{gd}}$) of 14 and $25 ~\mu \text{m}$ were fabricated and characterized. The destructive breakdown voltages (${V}_{\text{BR}}$) 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. [ABSTRACT FROM AUTHOR]