Growth of Bi2Sr2Ca2Cu3Oy superconducting films using the radio-frequency magnetron sputtering method

Bi 2 Sr 2 Ca 2 Cu 3 O y (Bi-2223) superconducting thin films have been prepared by radio-frequency magnetron sputtering using a mixture of helium and oxygen (He:O 2 = 4:1) as a sputtering gas. The films were deposited using the single powder targets with the various composition Bi:Sr:Ca:Cu = m:2:2:3 (m = 2-4). The phase of the film changed with use of the various compositions of targets, and a film with a Bi-2223 single phase was obtained using the target of m = 3. Furthermore, the phase and the crystallinity of the films depended on the substrate temperature and the gas pressure. We found the optimum sputtering conditions for the Bi-2223 film with good crystallinity, where the composition of the target, the substrate temperatures and the gas pressures were Bi-3223, 720 °C and 100 mTorr, respectively.