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

摘要

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.