Substrate temperature dependence of the properties of ZAO thin films deposited by magnetron sputtering

ZAO (ZnO:Al) transparent conductive thin films have been prepared by middle-frequency alternative magnetron sputtering with ZAO (98 wt.% ZnO+2 wt.% Al2O3) ceramic target. The influences of substrate temperature on the microstructure, optical, and electrical performances of ZAO films have been studied. UV-Vis and Van der Pauw investigated the visible transmittance, carrier concentration, and Hall mobility, respectively, while microstructure has been characterized by X-ray diffraction (XRD). The results show substrate temperature is a dominant factor for microstructure, optical, and electrical performances of ZAO thin films. The lowest resistivity obtained in this study was 4.6×10−4 Ω cm for the film with sheet resistance of 32 Ω, which was deposited at the substrate temperature of 250 °C and operation gas pressure of 0.8 Pa.