Characteristics of ZnO-Cu-ZnO multilayer films on copper layer properties

ZnO/Cu/ZnO multilayers on glass with different copper layer thickness were prepared by simultaneous RF magnetron sputtering of ZnO and dc magnetron sputtering of Cu. Different optimization procedure were used for good transparent conductive film. Several analytical tools such as spectrophotometer, scanning electron microscope (SEM), four point probes were used to explore the causes of the changes in electrical and optical properties. The sheet resistance of the structure was severely influenced by the deposition condition of both top ZnO and intermediate Cu layer. Effect of substrate temperature and annealing treatment on ZnO and Cu layer was analyzed. A sheet resistance of 10 Ω/sq and transmittance over 85% at 580 nm wavelength was achieved and could be reproduced by controlling the preparation process parameter. The results of an optimization condition of both oxide layers and metallic Cu layers are illustrated.