Ge Diffusion in Strained Si / Relaxed SiGe Heterostrucutures

We have studied the Ge diffusion in tensile-strained Si on relaxed SiGe. Two Ge concentrations have been used, 30 and 40%, in order to induce two different strain levels in the Si layer. Thermal budgets in-between 750 and 1000ºC for four hours have been tested. Higher thermal budgets lead as expected to a higher diffusion of Ge in sSi. The diffusion length is superior to 20 nm at 1000ºC, 4 hours. We have observed a slight increase of the diffusion coefficient of Ge in tensile strained silicon when the strain was increased.