Thermal Relaxation of Strained SiGe/Si Heterostructure

Abstract
The lattice strain of SiGe/Si relaxes upon annealing, but the relaxation speed decreases with time according to the change in the residual strain. This menchanism is expected to produce the metastability which has been observed in SiGe/Si strained structures. The deceleration process was interpreted comprehensively by the dislocation glide dynamics based on the thermal activation process, where the activation energy E depends linearly on the applied shear stress σ as high as ∼1 GPa. The stress dependence of the activation energy Δ E/Δσ obtained experimentally was ∼2×10-28 m3.