Si/Ge intermixing phenomena on Ge/Si(100) surface

Si/Ge interfacial intermixing phenomena have often been observed in epitaxial Ge overlayer growth on Si surfaces. Yet, it is not clear if this Si/Ge intermixing originates from an energetically favorable configuration or from nonequilibrium growth conditions. Using the first principles calculations we propose a model of defect-induced Si/Ge intermixing that is both energetically and kinetically favorable. Dimer-exchange and monomer-exchange processes are evaluated, and found to be energetically stable. The respective energy barriers in our calculations are 0.6 eV and 1.9 eV, and the estimated annealing temperatures are close to the experimental values.