Method for epitaxial lift-off for oxide films utilizing superconductor

Abstract

Novel structures and methods utilize layered copper oxide release materials to separate oxide films from growth substrates. Generally, the method comprises the steps of: first, forming a layered copper oxide sacrificial release material on a growth substrate, in the preferred embodiment being the high temperature superconductor YBCO grown on a compatible substrate such as LaAlO3, second, forming an oxide film on the layered copper oxide release material, in the preferred embodiment, a ferroelectric, an optical material or a oxide film compatible with further high temperature superconductor growth, such as SrTiO3 or CeO2, and third, etching the layered copper oxide release material so as to separate the oxide film from the growth substrate. Optionally, additional layers may be grown on the oxide film prior to etching. In the preferred embodiment, when high temperature superconducting devices are formed, the oxide films would be a material such as SrTiO3 or CeO2, upon which yet another high temperature superconducting film would be grown. After patterning and protecting the etched film, the structure may be etched. Generally, any of the layered copper oxide films, such as YBCO, TlCaBaCuO, LaSrCuOx and BiSrCaCuOx can be used. Oxide films having a substantially lower etch rate than the layered copper oxide materials incompatible with growth on the layered copper oxide materials may be utilized.