Sputtering deposition of perovskite thin films with atomic-scale controlled surface

Perovskite thin films of (001) PbTiO3(PT), 5 to 200 nm in thickness, were deposited on miscut (001) SrTiO3 (miscut angle 1.7°) by rf-magnetron sputtering. The surface of sputtered stoichiometric PT thin films comprised a periodic striped pattern which reflected the initial surface structure of the substrate. The periodic striped patterns comprised terraces and steps. The surface of the terraces region is atomically flat. The width of terrace and step height were 10 to 200 nm and 1 to 3 nm, respectively. The electron microscopic analysis suggests that the film shows a layer growth which corresponds to the Frank-van der Merwe mode. The layer growth is governed by a step-flow mode. Deposition under Pb-rich composition enhanced a two-dimensional nucleation and the two-dimensional nucleation was superposed on the striped patterns. The surface area of PT thin films increased under Pb-rich composition. It is confirmed that epitaxial growth on the miscut substrate is essential for the synthesis of perovskite thin films with an atomic-scale controlled surface.