Published online by Cambridge University Press: 26 February 2011
The effects of grown-in stress and applied external stress on the interdiffusion behavior in long-period Si0.7Ge0.3/Si is examined using x-ray diffraction and Raman Spectroscopy. Both symmetrically and asymmetrically–strained superlattices have been examined, and an activation energy for interdiffusion of 3.9 eV and 4.6eV have been obtained, respectively. In addition, an enhanced interdiffusion has also been measured when the asymmetrically–strained superlattice was subjected to an external tensile stress during annealing. In both cases, enhanced interdiffusion has been measured whenever the Si barrier layers experience tensile stress during annealing. The Raman results indicate that enhanced Ge diffusion into the Si barriers occur when these barriers are put under tensile stress. This result will be discussed in terms of the kinetics of defect formation and motion in the strained Si barriers.