Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}

Journal Article · Mon Nov 10 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4901726· OSTI ID:22391943

Kajdos, Adam P.; Stemmer, Susanne ^[1]

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1. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

We show that reflection high-energy electron diffraction (RHEED) can be used as a highly sensitive tool to track surface and resulting film stoichiometry in adsorption-limited molecular beam epitaxy of (001) SrTiO{sub 3} thin films. Even under growth conditions that yield films with a lattice parameter that is identical to that of stoichiometric bulk crystals within the detection limit of high-resolution x-ray diffraction (XRD), changes in surface reconstruction occur from (1 × 1) to (2 × 1) to c(4 × 4) as the equivalent beam pressure of the Ti metalorganic source is increased. These surface reconstructions are correlated with a shift from mixed SrO/TiO{sub 2} termination to pure TiO{sub 2} termination. The crossover to TiO{sub 2} surface termination is also apparent in a phase shift in RHEED oscillations observed at the beginning of growth. Comparison with prior results for carrier mobilities of doped films shows that the best films are grown under conditions of a TiO{sub 2}-saturated surface [c(4 × 4) reconstruction] within the XRD growth window.

• OSTI ID: 22391943
• Journal Information: Applied Physics Letters, Vol. 105, Issue 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADSORPTION
CARRIER MOBILITY
CRYSTALS
DOPED MATERIALS
ELECTRON DIFFRACTION
FILMS
LATTICE PARAMETERS
MOLECULAR BEAM EPITAXY
OSCILLATIONS
PHASE SHIFT
REFLECTION
STOICHIOMETRY
STRONTIUM OXIDES
STRONTIUM TITANATES
SURFACES
TITANIUM OXIDES
X-RAY DIFFRACTION