Structural control of epitaxially grown sputtered perovskite thin films

Thin films of perovskite Pb-Ti-O₃ families were heteroepitaxially grown by sputtering on (0001)sapphire and/or (001)SrTiO₃(ST). These epitaxial films contained microstructures, although X-ray diffraction analysis suggested formation of single crystal phase with three dimensional crystal orientation. Their microstructures were studied by the electron microscopy, atomic force microscopy, and spectroscopic ellipsometry so as to find factors which influence the formation of the microstructure. It was found that the orientation of the substrate surface and the chemical composition of adatoms during initial film growth strongly affected the formation of the microstructures. Sputtered PbTiO₃(PT) thin films under a stoichiometric condition on a miscut(001) ST(miscut 1.7 degree) realized the growth of continuous single crystal thin films of 10-100nm thick with extremely smooth surface with surface roughness less than 3nm. Deposition on a miscut substrate under a stoichiometric condition is essential to make continuous thin films of perovskite of single crystal phase.