Abstract
The surface structures of SrTiO3 thin films homoepitaxially grown by pulsed laser deposition (PLD) were studied using low temperature scanning tunneling microscopy (STM). We suggest microscopic pictures of the near-surface stoichiometry of SrTiO3 thin films, depending on their thickness and the growth mode. For comparison, an atomically ordered surface of SrTiO3 single crystal that is robust under typical thin film growth condition is shown. We atomically visualize the initial growth of homoepitaxial SrTiO3 thin film on this well-defined substrate, indicating that the surface structure of the substrate can be transferred to the film surface. Atomic-scale understanding of the surface structure of the substrate and the initial process of the thin film growth will provide new approach to realize oxide heterointerfaces that are controlled truly on an atomic scale.
