Fabrication of single-nanowire sensing devices by electron beam lithography

In this paper, we report on the feasibility of single nanowire devices fabrication by electron beam lithography. SnO₂ and ZnO nanowires bundles have been synthesized by vapor-liquid-solid technique, dispersed in isopropanol and then deposited on SiO₂/Si substrates. Once the nanowire has been selected, the electrodes have been patterned on the photoresist by the electron beam. Finally, after Pt sputtering and subsequent lift-off, we have obtained samples with SnO₂ or ZnO nanowire and Pt electrodes deposited on it. The electrical characteristics of the devices have been preliminary investigated by DC measurements and impedance spectroscopy. The SnO₂ single nanowire devices show a good sensitivity to relative humidity. The ZnO single nanowire device shows three orders of magnitude increase of the current when exposed to UV light and a fast recovery of the baseline in air when the UV light is switched off.