SURFACE SMOOTHNESS OF YBCO THIN-FILMS DEPOSITED BY RF-SPUTTERING

YBCO thin films were deposited on MgO by RE-sputtering The effects of substrate position during the deposition, substrate temperature and annealing conditions on film characteristics such as surface smoothness, crystallinity and electrical properties were investigated. The results of Talystep measurement showed that a smoothness of 5 nm with 0.4 mu m-thick YBCO film was obtained when the substrate was placed normal and around the sputtering target. The surface smoothness was affected not only by deposition condition but also by post-annealing. The suitable annealing condition was 900 degrees C for 60 min. A zero-resistance temperature as high as 85 K was obtained reproducibly and this value did not change over 150 days.