Unusual strain relaxation in SiGe/Si heterostructures

Abstract

Si 1−x Ge x films (x=0.22) epitaxially grown by ion beam-sputter deposition on (001) Si substrates were subjected to rapid and conventional thermal annealings at different temperatures. Strain measurements carried out by means of high-resolution x-ray diffraction exhibited strongly nonmonotonous strain dependencies on the annealing time. We observed short-time and long-time relaxation modes with activation energies of 4.6 and 1.3 eV, respectively, and unexpectedly, an additional mode of strain recovery at intermediate time durations with an activation energy of 1.6 eV. This behavior was attributed to processes that involve {113} two-dimensional defects, i.e., agglomerates of interstitials, which were identified by means of transmission electron microscopy.

Interrelations between defects in the Hg1−xCdxTe epilayers and their measured lattice parameters and composition

“…4,5,7 Point defects in semiconductors are studied in close relationship with self-and impurity-diffusion processes because they are extremely important to semiconductor doping. 11 Using modern HRXRD setup in the Bond mode of operation, it is possible to detect point defect concentrations on the level of 10 -5 and may be even 10 -6 of the atomic concentration. Hg 1-x Cd x Te system is unique in this sense because many point defects are created during layer growth and remain to be frozen at room and lower temperatures due to low defect diffusivity.…”

Structural coupling across the direct EuO/Si interface

“…It can be explained by tetragonal deformation of the Eu 2 O 3 layer. On the other hand, such deformation may be caused by a high density of defects [39,40]: the structural factor for Eu 2 O 3 is significantly smaller than that for EuO indicating low structural quality of the capping layer.…”