Low Reverse Conduction Loss β-Ga₂O₃ Vertical FinFET With an Integrated Fin Diode

In this work, a reverse conduction beta-phase gallium oxide ( $\beta $ -Ga ₂ O ₃ vertical FinFET with an integrated Fin diode (FD) is proposed to improve reverse conduction characteristics with little effect on the threshold voltage ( ${V}_{\text {th}}$ ) and breakdown voltage (BV). Its electrical characteristics are studied and analyzed by Sentaurus technology computer aided design (TCAD) simulation. The integrated FD achieves metal–insulator–semiconductor (MIS)-like conduction/blocking characteristics owing to the Fin channel combined with an Ohmic contact anode. In the reverse conduction state, the FD first realizes a very low reverse turn-on voltage ( ${V}_{\text {on}}$ ), and then forms the electron accumulation layers along the Fin sidewalls to improve reverse current capability; in the forward conduction and blocking states, the Fin channel of FD is pinched off by the MIS structures from the two sidewalls due to the work function difference between the source metal and $\beta $ -Ga ₂ O ₃ , without obvious influence on the forward conduction and blocking characteristics. Compared with the conventional FinFETs (C-FinFETs), the reverse conduction $\beta $ -Ga ₂ O ₃ vertical FinFET (RC-FinFET) reduces the ${V}_{\text {on}}$ by 71% with almost the same ${V}_{\text {th}}$ and BV values. The proposed $\beta $ -Ga ₂ O ₃ RC-FinFET achieves a low ${V}_{\text {on}}$ of 0.45 V, high ${V} _{\text {th}}$ of 1.6 V, BV of 2545 V, and Baliga’s figure of merit (BFOM) up to 1.41 GW/cm ² . In addition, compared to a field effect transistor (FET) externally connecting a freewheeling diode, the RC-FinFET reduces the parasitic inductance and the total chip area, enhancing its application potential for high-power and low-loss power conversion systems.