Diffusion of Ge below the Si(100) surface: theory and experiment
We have studied diffusion of Ge into subsurface layers of Si(100). Auger electron diffraction measurements show Ge in the fourth layer after submonolayer growth at temperatures as low as 500 degrees C. Density functional theory predictions of equilibrium Ge subsurface distributions are consistent with the measurements. We identify a surprisingly low energy pathway resulting from low interstitial formation energy in the third and fourth layers. Doping significantly affects the formation energy, suggesting that n-type doping may lead to sharper Si/Ge interfaces.
Uberuaga
BP
Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 and Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700, USA.
Leskovar
M
Smith
AP
Jonsson
H
Olmstead
M