Low-energy ion-beam bombardment for metal oxide nanowire surface cleaning and modification

Abstract

The paper presents results of study of the SnO2 nanowire chemoresistor treatment by means of low-energy Ne ion-beam bombardment. SnO2 nanowires were obtained by means of vapor-solid method at the temperature 900°C. Ti/Au (20/500 nm) electrical contacts to individual nanowires were deposited via consequent PVD deposition through the shadow mask under high vacuum conditions. Current versus voltage characteristics were measured in the range -10 to 10 volts both in high vacuum (P = 1x10-6 Torr) and in the oxygen presence (1x10-4 Torr). Cleaning and modification of nanostructure surface in situ was performed through the series of Ne bombardment cycles at the 275°C and Ne partial pressure PNe = 1x10-6 Torr. Established experimentally optimal Ne ion current has amounted to 1.15x10-4 A. Electrical conductance and gas sensing performance changing due to the NW interaction with ion beam were used to control ion bombardment effect. It was established that conductivity is increased by two orders and superficially modified NW response to hydrogen with oxygen background is also higher.