PURPOSE: To raise the superconductive transition temperature by alternately laminating a layer oxide superconducting thin film containing Bi, Cu and an alkaline earth metal as principal components and a layer oxide thin film containing Bi and Ta as principal components on a substrate.
CONSTITUTION: A substrate (MgO substrate) 15 such as MgO is heated at 600-700°C with a heater 16 and a Bi-Sr-Ca-Cu-O target 11 and a Bi-Ta-O target 12 arranged at places so as to focus on the substrate 15 in an Ar/O2 mixed atmosphere are sputtered. Sputtering vacuum deposition is carried out on the substrate 15 while controlling rotation of a shutter 13 installed in front of the targets and the rotation of an aperture 14 therein to alternately laminate a layer oxide superconducting thin film containing the Bi, Cu and alkaline earth metal (group IIa) as principal components and a layer oxide thin film containing the Bi and Ta as principal components. The resultant substrate is then heat- treated at 850-950°C to provide an oxide superconducting thin film. Furthermore, a Bi-containing oxide is laminated to a Cu- and an alkaline earth metal- containing oxide to afford an oxide thin film, which is then alternately laminated to an oxide thin film prepared by laminating a Bi-containing oxide to a Ta-containing oxide to afford the objective oxide superconducting thin film.
NISHIKURA KUMIKO
ICHIKAWA HIROSHI
SETSUNE KENTARO
