Ion beam patterning of spin-on metalorganic precursors and formation of high T c superconductors

A new technique using ion beams to produce patterned thin films of the high-temperature perovskite superconductor YBa2Cu3O7−x from spin-on metalorganic precursors is described. Spin-coated precursor films are irradiated through a stencil mask with 2.5 MeV He+ ions, developed in solvent to remove unexposed material, and the remaining patterns are pyrolyzed. Black films of YBa2Cu3O7−x with pattern dimensions on the millimeter scale exhibit orientation with the c axis perpendicular to the film after heat treatments of 990 °C for 3 min. The conductivity of a highly oriented, ∼0.4-μm-thick patterned film is characterized by onset of the superconducting transition at 84 K and zero resistivity at 68 K, similar to those of an unirradiated film given the same thermal treatment. Studies on the nature of the ion beam exposed material are discussed.