Process for producing bismuth-based oxide superconducting films

Claim 1

A process for producing a bismuth-based oxide superconductor film having a crystal structure in which atomic layers having different chemical compositions are laminated along the film thickness direction and each of unit cells of said crystal structure consists of a pair of lower and upper half cells having half the height of the unit cell and each bordered with a cleavage plane at the top and the bottom thereof, said process comprising the steps of: depositing, on a substrate, amorphous atomic layers respectively having chemical compositions corresponding to those of atomic layers of said crystal structure, layer by layer in the film thickness direction to form an amorphous subunit of said amorphous atomic layers laminated in a number and an order corresponding to said lamination of said atomic layers of said half cell of said crystal structure, lowermost and uppermost amorphous atomic layers defining a plane corresponding to said cleavage plane; heating said subunit in an oxygen-containing atmosphere to crystallize the subunit; and repeating a cycle of said deposition and crystallization steps to form a number of the crystallized subunits required to form said oxide superconductor film.