Effect of the sign of misfit strain on the formation of a dislocation structure in SiGe epitaxial layers grown on Si and Ge substrates

Comparative analysis of the specific features of the formation of a dislocation structure in the single-layer epitaxial heterostructures Si_1?xGe_x/Si and Ge_1?ySi_y/Ge is performed. It is ascertained that, at a relatively low lattice mismatch between an epitaxial layer and a substrate, the sign of misfit strain at the interface significantly affects the processes of defect formation. The most probable reasons for the observed phenomena are analyzed with allowance for the specific features of the state of the ensemble of intrinsic point defects in epitaxial layers subjected to elastic strains of a different sign.