Properties of Ga2O3(Gd2O3)/GaN metal–insulator–semiconductor diodes

${\mathrm{Ga}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}({\mathrm{Gd}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{),}$ electron beam evaporated from a single crystal ${\mathrm{Ga}}_{\mathrm{5}}{\mathrm{Gd}}_{\mathrm{3}}{\mathrm{O}}_{\mathrm{12}}$ garnet, was ex situ deposited on molecular beam epitaxy grown GaN of Ga-polar surface. Using capacitance–voltage measurement, accumulation and depletion behavior was observed in the ${\mathrm{Ga}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}({\mathrm{Gd}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{)/}\mathrm{GaN}$ metal–oxide–semiconductor diodes, with an interfacial density of states less than ${10}^{11}\hspace{0.5em}{\mathrm{cm}}^{\mathrm{-2}}\hspace{0.17em}{\mathrm{eV}}^{\mathrm{-1}}.$ The ${\mathrm{Ga}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}({\mathrm{Gd}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{)/}\mathrm{GaN}$ interface remains intact with the samples subject to rapid-thermal annealing up to 950 °C, as studied from x-ray reflectivity measurements.