ZnO Nanoparticle Formation in <sup>64</sup>Zn<sup>+</sup> Ion Implanted Al<sub>2</sub>O<sub>3</sub>

Abstract

ZnO nanoparticles (NPs) formed in (-1012) sapphire substrates have been studied. The NPs were formed by implantation of 64Zn+ ions followed by furnace annealing in oxygen atmosphere for 1h at elevated temperatures. The radiation defects and Zn implant profiles were investigated by Rutherford backscattering spectroscopy of He+ ions with energy of 1.7MeV with scattering angle of 160o at Van de Graff accelerator using the ion channeling technique (RBS/CT). The surface morphology was studied by atomic force microscopy (AFM) and scan electron microscopy in secondary emission mode (SEM-SE). The distribution of Zn implant profiles was analyzed by secondary ion mass-spectrometry (SIMS). Identification of the phase content of the materials was carried out by X-ray photoelectron spectroscopy (XPS). In as implanted samples, a near-surface amorphization layer was formed, and in this layer the surface voids were created. After annealing in temperature range of 600-900°C the ZnO phase was synthesized in sapphire substrate. After annealing at 900°C one can see the phase variation from ZnO/Zn phases at sample surface to metal Zn phase in sample body at a depth of 40nm. Annealing at temperatures above 900°C leads to disappearing of ZnO phase and creating of ZnAl2O4 phase.