Selective alignment of a ZnO nanowire in a magnetic field for the fabrication of an air-gap field-effect transistor

An air-gap field-effect transistor (FET) was prepared by selectively aligning a Ni-capped ZnO nanowire in a magnetic field on a pre-fabricated electrode patterns formed by lithography. It was demonstrated that the magnetic alignment technique could be applied effectively to the fabrication of air-gap nanowire FETs with desired circuit configurations. This device showed operational characteristic strongly dependent on the possible surface adsorbates originating from the negatively charged oxygen related species, as compared to the back-gate nanowire FET separately prepared for comparison. These results will illuminate the prospect of realizing producible matrix-type devices based on one-dimensional nanostructures such as logic circuits and biochemical sensors.