Growth kinetics of homoepitaxial strontium titanate films by interrupted pulsed laser deposition

Abstract

The effects of the initial surface state on the evolution kinetics of the surface morphology of strontium titanate (STO) films was investigated by in-situ monitoring the intensity variations of reflection high-energy electron diffraction (RHEED). In order to create various surface states prior to subsequent depositions, we intentionally interrupted the pulsed laser deposition (PLD) at various points during the whole deposition course to perform in-situ annealing over various periods of time. The depth of the initial drop of RHEED intensity, which is a direct indication of changes in surface step densities, shows two distinct time scales. The results suggest that the evolution of a growing surface, and hence the ultimate film surface morphology, may be manipulated by controlling the number density of the as-deposited growing islands through interrupted annealing.