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Surface Science, Volume 609, March 2013, Pages 157-160.
Hidehito Asaoka, Tatsuya Yamazaki, Kenji Yamaguchi, Shin-ichi Shamoto, Sergey Filimonov, Maki Suemitsu.
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan and
Department of Physics, Tomsk State University, Tomsk 634050, Russia and
Research Institute of Electrical Communication, Tohoku University, Aoba-ku, Sendai 980-8577, Japan.
Abstract
We have focused on stress measurements during Bi termination of Si (111) and Ge growth on this Bi-mediated Si (111). In order to obtain information on both the surface stress and the surface structure simultaneously, we have combined the surface-curvature and the reflection-high-electron-energy-diffraction instrumentations in an identical ultrahigh vacuum system. We find the Bi-terminated Si (111) √3 × √3-{Beta} surface releases 1.8 N/m (= J/m2), or (1.4 eV/(1 × 1 unit cell)), of the surface energy from the strong tensile Si (111) 7 × 7 reconstruction. Subsequent Ge deposition on the Bi-terminated Si surface develops a compressive stress, which oscillates with a period corresponding to the growth of a single bilayer. The real-time stress measurement provides a direct evidence for this oscillatory stress relaxation in the layer-by-layer growth.
