DIFFUSION IN STRAINED SI(GE)

Experiments on Si-rich SiGe layers show an exponential increase in Ge diffusion and an exponential decrease in B diffusion as a function of compressive strain, indicating a linear dependence of activation energ y on strain. The effect arises from the structural relaxation of the l attice around the defect mediating diffusion (inward for a vacancy, ou tward for an interstitial). We infer the mechanisms of Ge and B diffus ion in strain-free and compressively strained Si(Ge) at T < 1030-degre es-C, and draw some general conclusions on strain-modified diffusion i n crystalline solids.