Current Aperture Vertical β-Ga2O3 MOSFETs Fabricated by N- and Si-Ion Implantation Doping

Depletion-mode vertical Ga2O3 metal-oxidesemiconductor field-effect transistors featuring a current aperture were developed on a halide vapor phase epitaxial drift layer grown on a bulk beta-Ga2O3 (001) substrate. Three ion implantation steps were employed to fabricate the n ++ source regions, lateral n channel, and p current blocking layers, where Si and N were selected as the donor and deep acceptor dopant species, respectively. The transistors delivered a drain current density of 0.42 kA/cm(2), a specific on-resistance of 31.5m Omega.cm(2), and an output current on/off ratio of over 108. High-voltage performance of the present devices was hampered by a large gate oxide field in the off-state causing high gate leakage, a limitation that can be readily overcome through optimized doping schemes and an improved gate dielectric. The demonstration of a planar-gate vertical Ga2O3 transistor based on a highly manufacturable all-ion-implanted process greatly enhances the prospects for Ga2O3-based power electronics.