Domain-sensitive in situ observation of layer-by-layer removal at Si(100) in H2 ambient

Double-layer step formation on Si(100) substrates is a crucial prerequisite for antiphase-domain free III–V compound semiconductor heteroepitaxy. Due to its unequaled relevance in microelectronics, the (100) oriented surface of silicon is by far the most studied semiconductor surface. However, Si(100) preparation in hydrogen process gas ambient, which is commonly employed for Si and III–V device preparation, is completely different from preparation in ultra-high vacuum due to strong interaction between H2 and the Si surface, leading to a kinetically driven different step formation. Here, we observe chemical layer-by-layer removal of surface atoms from the terraces at the Si(100) surface during annealing in hydrogen ambient. Mutually perpendicularly oriented dimers on subsequently removed monolayers induce oscillations in the in situ reflection anisotropy spectroscopy (RAS) signal. Scanning tunneling microscopy measurements support a model, where surface 5 Author to whom any correspondence should be addressed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. New Journal of Physics 15 (2013) 113049 1367-2630/13/113049+10$33.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft