Realization of highly reproducible ZnO nanowire field effect transistors with n-channel depletion and enhancement modes

The authors demonstrate the highly reproducible fabrication of n-channel depletion-mode (D-mode) and enhancement-mode (E-mode) field effect transistors (FETs) created from ZnO nanowires (NWs). ZnO NWs were grown by the vapor transport method on two different types of substrates. It was determined that the FETs created from ZnO NWs grown on an Au-coated sapphire substrate exhibited an n-channel D mode, whereas the FETs of ZnO NWs grown on an Au-catalyst-free ZnO film exhibited an n-channel E mode. This controlled fabrication of the two operation modes of ZnO NW-FETs is important for the wide application of NW-FETs in logic circuits. (c) 2007 American Institute of Physics.