Effects of growth rate and buffer-layer on Bi2Sr2CaCu2Oy thin ®lm fabrication

The effect of the growth rate on the Bi2Sr2CaCu2Oy (Bi2212) thin ®lm quality on MgO substrate is investigated at several growth rates from 0.175 to 3 nm/min. The maximal step height on the ®lm surface is improved from about 100 to 6 nm by the reduction of growth rate to 0.5 nm/min and simultaneously the superconducting critical temperature attaining to a zero resistance Tc…R ˆ 0†, is also improved from 50 to 63 K. The surface morphologies of the upmost Bi-superconducting thin ®lms with the intermediate layers on MgO substrate is also studied in contrast to that deposited directly on the MgO substrate. # 2001 Elsevier Science B.V. All rights reserved.