Adjusting island density and morphology of the SrTiO3(110)-(4 × 1) surface: Pulsed laser deposition combined with scanning tunneling microscopy

S. Gerhold, M. Riva, B. Yildiz, M. Schmid, U. Diebold

Institut für Angewandte Physik, Technische Universität Wien, 1040 Wien, Austria
Laboratory for Electrochemical Interfaces, Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, U.S.A.

Surf. Sci. 651 (2016) 76-83

The first stages of homoepitaxial growth of the (4 × 1) reconstructed surface of SrTiO3(110) are probed by a combination of pulsed laser deposition (PLD) with in-situ reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Considerations of interfacing high-pressure PLD growth with ultra high vacuum surface characterization methods are discussed, and the experimental setup and procedures are described in detail. The relation between RHEED intensity oscillations and ideal layer-by-layer growth is confirmed by analysis of the STM images after deposition of sub-monolayer amounts of SrTiO3. For a quantitative agreement between RHEED and STM results one has to take into account two interfaces: the steps at the circumference of islands, as well as the borders between two different reconstruction phases on the islands themselves. Analysis of STM images taken after one single shot reveals an exponential decrease of the island density with increasing substrate temperature. This behavior is also directly visible from the temperature dependence of the relaxation times of the RHEED intensity. Moreover, the aspect ratio of the islands changes considerably with temperature. The growth mode depends on the laser pulse repetition rate, and can be tuned from predominantly layer-by-layer to the step-flow growth regime.

Corresponding author: Michele Riva. Reprints also available from Ulrike Diebold (diebold at iap_tuwien_ac_at).

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