Influence of Substrate Temperature on the Al and Zr Co-Doped ZnO Thin Films Prepared by RF Magnetron Sputtering

Abstract

ZnO doped Al2O3and ZrO2(ZAZO) thin films were deposited by the radio frequency magnetron sputtering on substrate temperature with 100°C, 150°C, 200°C, 250°C and 300°C. The surface morphology and electrical properties of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and four-probe tester. The results showed that the substrate temperature obviously influenced the grain size of ZAZO films. The ZnO thin film had the largest crystallization orientation for the (002) peak and the smallest FWHM value at substrate temperature of 250°C. As the temperature increasing, the resistance of films gradually decreased till reaching a minimum at 250°C and then rised. Due to the increasing of Al and Zr concentrations into ZnO lattice, the Al ions created an abundance number of free electrons in the ZnO lattice, and in turn, the electrical conductivity increased. In addition, the improvement of film in the crystalline state results in the film resistivity decreases.