Regensburg 2013 – wissenschaftliches Programm

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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

Montag, 11. März 2013, 16:00–20:00, Poster A

In situ observation of monolayer removal on Si(100) in H₂ ambient — •Sebastian Brückner^{1, 2}, Peter Kleinschmidt³, Oliver Supplie², Henning Döscher^{1, 2}, and Thomas Hannappel^{2, 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.