Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 29: Poster Session: Spintronics; Spin-controled transport; Topological insulators; Interfaces / Surfaces; Magnetic semiconductors
HL 29.23: Poster
Monday, March 11, 2013, 16:00–20:00, Poster A
In situ observation of monolayer removal on Si(100) in H2 ambient — •Sebastian Brückner1, 2, Peter Kleinschmidt3, Oliver Supplie2, Henning Döscher1, 2, and Thomas Hannappel2, 3 — 1Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe — 2TU Ilmenau, Institut für Physik, Fachgebiet Photovoltaik — 3CiS Forschungsinstitut für Mikrosensorik und Photovoltaik, Erfurt
Step formation is crucial for subsequent heteroepitaxial growth of III-V semiconductors on Si(100). Single-layer steps on Si(100) are associated with the presence of two domains with different dimer orientations on the reconstructed surface, leading to the initiation of anti-phase domains (APDs) in the epitaxial III-V layer. Therefore, double-layer steps are required to prevent APD formation.
Here, we used reflection anisotropy spectroscopy (RAS) to study the preparation of Si(100) surfaces during chemical vapor deposition (CVD) processing. Interaction between H2 process gas and Si(100) surface strongly influences the surface structure. Oscillations in the RAS signal during annealing in H2 ambient indicate alternating formation of preferential A- and B-type domains on Si(100) due to Si removal. Based on scanning tunneling microscopy measurements we conclude that formation and anisotropic expansion of vacancies on the terraces induces a layer-by-layer removal mechanism. In situ RAS enables precise control of Si removal and domain formation on Si(100) surfaces.