GRAPHOEPITAXY OF YBA2CU3O7 THIN-FILMS

We report on the graphoepitaxial growth of YBa2Cu3O7 (YBCO) thin films on LaAlO3 (LAO) substrates textured with submicron features. This is the first use of a substrate microstructure to template and control the morphology of a thin film. Two-dimensional close-packed crystalline monolayers of polystyrene spheres 482 nm in diameter are used as lithographic masks for the ion milling of arrays of conical posts in the substrates. This regular pattern is reflected in the growth of the YBCO film which is at once epitaxial to the substrate and disrupted on the same length scale as the substrate texture. The YBCO thin films are structurally and electrically of the same quality as films deposited on untreated substrates.