Electrical properties of ZnO nanowire field effect transistors with varying high-$k$ $Al2O3$ dielectric thickness

We investigated the electronic properties of ZnO nanowire combined with the scaled high-$k$ $Al2O3$ dielectrics using metal-oxide-semiconductor and field effect transistor (FET) device structures. We found that $Al2O3$ dielectric material can significantly reduce leakage currents when the applied voltage was restricted less than the transition voltage of direct tunneling to Fowler–Nordheim tunneling. The ZnO nanowire FETs with $Al2O3$ dielectrics exhibited the increase in electrical conductance, transconductance, and mobility and the threshold voltage shifted to the negative gate bias direction with decreasing $Al2O3$ dielectric layer thickness.