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 over the temperature range of 770–920C. The Si–Ge interdiffusivity was found to increase by 2.2× 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 increased 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.Xia, M.Canonico, J.L.Hoyt: Semiconductor Science and Technology, 2007, 22, S55-8