Mechanism Analysis and Small-Signal Modeling of β -Ga 2 O 3 -Based Enhancement-Mode FinFETs

In this article, a β-gallium oxide (β -Ga2O3)-based enhancement-mode (E-mode) FinFET is proposed, in which the combination of the Fin channels and recessed gate enables synergistic regulation of the threshold voltage and gate breakdown voltage. The device exhibits a threshold voltage(VTH) of + 0.4 V, a gate overdrive voltage up to 14.6 V, and a current density of 243 mA/mm. By employing heavily doped source/drain regions, an ohmic contact resistance as low as 0.76 Ω·mm and a specific on-resistance (Ron,sp) of 1.73 mΩ·cm2 are achieved. Furthermore, comprehensive small-signal RF measurements are performed, based on which an accurate equivalent circuit model is established through systematic fitting and parameter extraction. The extracted intrinsic and parasitic parameters enable quantitative analysis of the factors limiting the high-frequency performance, yielding fT/fMAX values of 1.5–3.5 GHz for the β-Ga2O3-based E-mode FinFET.