Control of growth mode in SrTiO3 homoepitaxy under 500°C

Homoepitaxial SrTiO3 thin films were grown by laser molecular beam epitaxy. The growth mode was determined by in-situ reflective high energy electron diffraction, and the surface of the films was studied by ex-situ atomic force microscopy. At the deposition rate of 0.16Angstrom/sec and the laser energy density of 6J/cm(2), layer-by-layer growth was observed above 460degreesC substrate temperature, while the Stranski-Krastanov growth mode, that is layer-by-layer growth plus island growth mode, prevailed between 460degreesC and 410degreesC. On further decreasing the substrate temperature, the island growth was determined under 410degreesC. With the optimization of deposition process in terms of laser energy density and deposition rate, the lowest crystallization temperatures of SrTiO3 films grown in layer-by-layer growth mode were obtained as low as 280degreesC. The effects of laser energy density on growth temperature were studied. (C) 2004 American Institute of Physics.