Fast Switching Quasi-Inversion-Channel β -Ga 2 O 3 UMOSFET

This paper presents a comprehensive investigation into the dynamic switching characteristics of a vertical β-Ga₂O₃ UMOSFET. A 400-mA vertical quasi-inversion-channel β-Ga₂O₃ UMOSFET fabricated using a self-aligned process was demonstrated with a specific on-resistance of 13.2 mΩ·cm2and a threshold voltage of 2.9 V. Through double-pulse testing at bus voltages up to 200 V, the device presents excellent switching speed, achieving an outstanding turn-on time of 10.6 ns and a turn-off time of 73.4 ns. In addition, inter-terminal capacitances are characterized and used to calculate the switching charges, including total gate charge of 1.37 nC and Miller charge of 0.26 nC, which can account for the high switching speed. Device figure of merits (FOMs) and switching frequency were then derived. Our β-Ga₂O₃ UMOSFETs exhibit superior switching FOMs when compared with commercial Si power transistors of similar current rating. These results offer the critical insights into the dynamic performance of β-Ga₂O₃ UMOSFETs, confirming their significant potential for next generation power electronics.