Initial stages of Sb-mediated growth of Ge on Si(100): A first-principles study

The initial stages of Sb-mediated growth of Ge on Si(100) surface is studie d using first-principles calculations. The bonding geometry and electronic configurations are investigated after a single Ge atom, a single Ge dimer, and two Ge dimers adsorption in details. Our calculations show that the ads orbed Ge dimers are located between Sb dimer rows. A single Ge dimer hardly alter the neighboring Sb-Sb dimer bond lengths. However, two Ge dimers can greatly weaken the Sb-Sb bonds and initiate the exchange of Ge and Sb atom s. These results are consistent with the experimental observations.