A model was presented for the interdiffusion of silicon and germanium in Si1−xGex/Si superlattice structures. Both a vacancy exchange mechanism and an interstitial diffusion mechanism were considered in the proposed model. The effects of Ge upon the diffusion properties of the superlattice were also considered and conservation of lattice-site constraints was accounted for. The results from the model were compared with experimental Ge interdiffusion profiles for samples annealed at 770 to 1125C in inert or oxidizing ambients, for experimental samples containing up to 30%Ge. For annealing temperatures of up to 1075C, a vacancy-exchange mechanism was sufficient to describe the interdiffusion mechanism in Si1−xGex/Si superlattice structures. At higher annealing temperatures, interstitial diffusion dominated the interdiffusion process.

Modeling Germanium Diffusion in Si1−xGex/Si Superlattice Structures. M.Hasanuzzaman, Y.M.Haddara, A.P.Knights: Journal of Applied Physics, 2009, 105[4], 043504