The Si–Ge interdiffusivity in epitaxial strained Si/Si1-yGey/strained Si/relaxed Si1-xGex and strained Si/relaxed Si1-xGex heterostructures was investigated for Ge fractions between 0 and 0.56 at 770 to 920C. The Si/Ge interdiffusivity was found to increase by 2.2 times for every 10% increase in local Ge fraction for interdiffusion in strained Si/relaxed SiGe structures. Significantly enhanced Si–Ge interdiffusion was observed in structures with Si1-yGey layers under biaxial compressive strain. The interdiffusivity increases by 4.4 times for every 0.42% increase in the magnitude of biaxial compressive strain. These results were incorporated into an interdiffusion model that successfully predicts the interdiffusion in epitaxial SiGe heterostructures.

Interdiffusion in Strained-Si/Strained-SiGe Epitaxial Heterostructures. G.(M.)Xia, M.Canonico, J.L.Hoyt: Semiconductor Science and Technology, 2007, 22, S55-8