Regensburg 2007 – scientific programme
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DS: Fachverband Dünne Schichten
DS 20: Symposium: Real Time Growth Studies I
DS 20.1: Talk
Thursday, March 29, 2007, 09:30–09:45, H32
Real-time studies of MBE growth using electron and synchrotron x-ray diffraction — •Wolfgang Braun1, Dillip Kumar Satapathy2, Vladimir Kaganer1, Bernd Jenichen1, Lutz Däweritz1, and Klaus Ploog1 — 1Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin — 2Paul Scherrer Institut, Swiss Light Source, CH-5232 Villigen PSI, Switzerland
Using reflection high-energy electron diffraction (RHEED) and synchrotron x-ray diffraction, we can study epitaxial growth phenomena in great detail under realistic growth conditions. Whereas RHEED has a superior surface sensitivity, but is hampered by usually strong multiple scattering effects, x-ray diffraction allows a straightforward quantitative analysis using kinematical scattering theory. In addition, x-rays can penetrate deeply into the material, allowing us to follow the formation of a heteroepitaxial interface even as it is buried by continued deposition.
The growth of MnAs on GaAs(001) by molecular beam epitaxy serves as an example to demonstrate the synergy of both methods. Whereas RHEED offers a detailed view of the initial nucleation phase, x-ray diffraction allows us to follow the formation of a strongly anisotropic, periodic array of misfit dislocations at the heterointerface that is governed by the misfit and the bonding between film and substrate. A fascinatingly rich and complex sequence of growth stages unfolds, taking us beyond the standard classification of Volmer–Weber and Stranski–Krastanov growth.