Published online by Cambridge University Press: 25 February 2011
Raman scattering and x ray diffraction were used to study the effects of annealing on a Ge/Si superlattice that had been grown upon a Ge0.4Si0.6 alloy buffer layer which distributes the strain between the layers. Anneals above 910K caused substantial mixing at the Ge-Si interfaces. The interdiffusion coefficients obtained from the x-ray data were found to obey an Arrhenius relation with an activation energy of 3.1±0.2eV. Initial intermixing seems to be dominated by the diffusion of Si atoms into the Ge layers via a vacancy mechanism.