Epitaxial prodn. of high temp. superconducting layer on substrate - by sputtering intermediate metal oxide layer on substrate, and then depositing superconducting layer

摘要

Epitaxial prodn. of a high temp. superconducting layer on an epitaxial surface of a Si substrate is claimed, in which an intermediate layer of metal oxide material is initially sputtered at elevated temp. onto the substrate, and then the superconducting layer is deposited on this. The lattice constant of the metal oxide is compatible with the substrate material and also the superconductor. The novelty is that the intermediate layer (4) is formed by : (a) initially applying a base layer (4a) of a few atoms thick (d1) of at least one metallic component of the intermediate layer onto the substrate (5) oxidised on its surface (5a) to SiO2 using an O2-free gas, so that at elevated temp. the metallic component is oxidised and the SiO2 reduced; and (b) depositing the metal oxide intermediate layer (4) onto the base layer (4a). ADVANTAGE - The metal oxide intermediate layer is formed as a buffer layer so that specific pre-cleaning of the substrate surface is not required.