Thin channel β-Ga2O3 MOSFETs with self-aligned refractory metal gates

We report the first demonstration of self-aligned gate (SAG) β-Ga₂O₃ metal-oxide-semiconductor field-effect transistors (MOSFETs) as a path toward eliminating source access resistance for low-loss power applications. The SAG process is implemented with a subtractively defined and etched refractory metal, such as Tungsten, combined with ion-implantation. We report experimental and modeled DC performance of a representative SAG device that achieved a maximum transconductance of 35 mS mm^-1 and an on-resistance of ∼30 Ω mm with a 2.5 μm gate length. These results highlight the advantage of implant technology for SAG β-Ga₂O₃ MOSFETs enabling future power switching and RF devices with low parasitic resistance.