Impact of Different Gate Metals on the RF Performance of Gallium Oxide MOSFET

The performance of gallium oxide MOSFET is limited due to the issues associated with the requirement of good contact materials for gate electrode. The single metal layer at the gate electrode does not possess all the suitable material properties such as good adhesive behavior, high work function, and low specific resistance. In this work, the effect of different metals, to modulate the work function of depletion-type gallium oxide MOSFET is studied so as to improve its RF performance. The advantage of work function modulation and energy band aligned gate electrode shows low specific contact resistivity with a good ohmic contact. The key figure of merits (FOMs) for its RF performance investigation includes intrinsic capacitances (C gs & C gd ), output conductance (g d ), transconductance (g m ), and cut-off frequency (f T ). This work elucidates that the Ti/Au metal stack with high f T value found to be superior for RF applications.