Nb₂O₅ high-k dielectric enabled electric field engineering of <i>?</i>-Ga₂O₃ metal–insulator–semiconductor (MIS) diode

We demonstrate an Nb$_{2}$O$_{5}$/$\beta$-Ga$_{2}$O$_{3}$ metal-insulator-semiconductor (MIS) hetero-junction diode with Nb$_{2}$O$_{5}$ as the high-k dielectric insulator for more efficient electric field management resulting in enhanced breakdown characteristics compared to a $\beta$-Ga$_{2}$O$_{3}$ Schottky barrier diode. The films were grown using atomic layer deposition and exhibited high constant of 50. resulted 5$\times$ lower at metal/dielectric interface MIS metal/$\beta$-Ga$_{2}$O$_{3}$ With good electron conduction forward bias enabled by negative band offset w.r.t $\beta$-Ga$_{2}$O$_{3}$, design led 3$\times$ improvement reverse blocking voltage slight trade-off specific on-resistance. Overall, 3.3$\times$ increase power figure merit was observed (3.25 MW/cm$^2$ 10.8 diode). A detailed analysis energy line-up, current transport mechanisms are also presented analytical modeling 2-D TCAD simulations.