ZnO nanowire formation by two-step deposition method using energy-controlled hollow-type magnetron RF plasma

Abstract

ZnO nanowire was produced in RF (radio frequency) discharge plasma. We employed here a two-step deposition technique. In the 1st step, zinc atoms were sputtered from a zinc target to create zinc nuclei on a substrate before the growth of ZnO nanostructure. Here, we used pure argon plasma for physical sputtering. In the 2nd step, we employed an oxygen discharge mixed with argon, where oxygen radicals reacted with zinc nuclei to form ZnO nanostructures. Experimental parameters such as gas flow ratio and target bias voltage were controlled in O 2/Ar plasma. Properties of the depositions were analysed by SEM and Raman spectroscopy. We found that many folded and bundled nanowires formed in the 2nd step. The diameter of wires was typically 10-100nm. We also discussed a growth mechanism of ZnO nanowires. Copyright © 2011 Hideki Ono and Satoru Iizuka.