Thin film processing for high-Tc superconductors of the Bi-system

Basic thin film deposition processes for controlled deposition of the high-Tc superconductors of the Bi-systems are described. The layered structures of Bi-oxide superconductors are fabricated by a multitarget sputtering process. The multitarget sputtering process realizes the controlled deposition of single phase Bi-oxide superconductors, Bi2O2·2SrO·(n-1)CaO·nCuO2 for n=1 to 5. The minimum thickness controlled by the multitarget sputtering is a half crystal unit-cell of around 15 A, and the superlattices comprising (AkBk)·m, where A and B denote the Bi-oxide superconductors with different numbers of Cu--O layers, could be fabricated for k>1, although ion mixing takes place during the sputtering deposition due to the bombardment of the highly energetic sputtered adatoms. Multitarget sputtering will be available for the fabrication of the artificially-made layered oxide superconductors (ALOS)