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O: Fachverband Oberflächenphysik

O 27: Poster Session I (Methods: Scanning probe techniques; Methods: Atomic and electronic structure; Methods: Molecular simulations and statistical mechanics; Oxides and Insulators: Clean surfaces; Oxides and Insulators: Adsorption; Oxides and Insulators: Epitaxy and growth; Semiconductor substrates: Clean surfaces; Semiconductor substrates: Epitaxy and growth; Semiconductor substrates: Adsorption; Nano- optics of metallic and semiconducting nanostructures; Electronic structure; Methods: Electronic structure theory; Methods: other (experimental); Methods: other (theory); Solutions on surfaces; Epitaxial Graphene; Surface oder interface magnetism; Phase transitions; Time-resolved spectroscopies)

O 27.60: Poster

Dienstag, 24. März 2009, 18:30–21:00, P2

In-situ RAS analysis of homo- and hetero-epitaxial GaP(100) surfaces grown by MOVPE — •Henning Döscher, Sebastian Brückner, and Thomas Hannappel — Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, 14109 Berlin

Control over the atomic properties of III-V compound semiconductor surfaces is of crucial importance for the preparation of well-defined hetero-interfaces in many thin film devices, e.g. solar cells, lasers, and LEDs. Reflectance anisotropy spectroscopy (RAS) is an extremely surface sensitive optical probe applicable for in-situ measurements in the MOVPE environment. The MOVPE deposition of gallium phosphide on Si(100) is studied here as an exemplary model system for the hetero-epitaxial III-V growth on non-polar substrates since this material combination represents an almost perfect lattice match.

The created hetero-interface gives rise to the formation of anti-phase domains (APDs) according to the step structure of the substrate, which are considered as a crucial defect mechanism in these samples. Recently, RAS was applied for quantitative in-situ measurements for APDs on the surface of GaP/Si(100) thin films. The success of this approach depends on the correct consideration of all influences on the structure and intensity of the characteristic RA spectra. In the case of GaP(100) surfaces, not only the reconstruction, but also the sample temperature and the applied preparation route have to be regarded. In the investigated thin film system additional signal contributions arise due to APD content and interference with the interfacial reflection, which potentially is anisotropic in itself.