Heteroepitaxial growth behavior of SrRuO3/SrTiO3(001) by pulsed laser deposition

Abstract

Heteroepitaxial growth behavior of SrRuO3/SrTiO3(001) thin films during early stages by pulsed laser deposition was investigated using synchrotron x-ray scattering, atomic force microscopy, and high-resolution transmission electron microscopy. We find that three-dimensional (3D) SrRuO3(110) islands of similar to1500 Angstrom in diameter grow at an initial stage of growth (30 Angstrom in thickness), in contrast to the two-dimensional layer growth previously reported in thick (3000 Angstrom) films by off-axis sputtering. Interestingly, the 3D islands are coherently strained to the substrate, possessing a very narrow mosaic distribution of 0.007degrees half width at half maximum. On top of the existing well-aligned islands, poorly aligned 3D islands of much smaller sizes progressively grow, reducing the interfacial strain while maintaining the small surface roughness of 9 Angstrom up to the film thickness of 420 Angstrom. (C) 2002 American Institute of Physics.