Working Pressure Dependence of Structure and Optical Performance of Zinc Oxide Thin Films by Magnetron Sputtering

Abstract

Zinc oxide (ZnO) thin films were grown by magnetron sputtering onto glass substrates employing a sintered ceramic target and pure argon gas. The influence of working pressure on structure and optical performance of the thin films were studied by the measurements of X-ray diffraction (XRD) patterns and optical transmission spectra. The optical energy gap of the ZnO thin film were calculated according to the Taucs law. The results demonstrate that all the ZnO thin films have preferred orientation along (002) direction. The working pressure affects not only the structure parameters such as lattice constant, strain and stress in the plane of the film, but also the optical transmittance and energy gap of the ZnO thin films. The ZnO thin film deposited at the working pressure of 0.5 Pa exhibits the maximum average visible transmittance of 86.6%, a compressive stress of 1.72×109 Pa, and an optical energy gap of 3.273 eV.