Long-Range Stresses Generated by Misfit Dislocations in Epitaxial Films

摘要

For the first time, an equation is derived that relates the misfit parameter f, the number of misfit dislocation (MD) families, and the distances between MDs of the same family, and the projection value of edge Burger's vector component on the interface. The equation is valid for various interface boundaries (hkl). To derive this equation, the long-range normal and shear stresses associated with MD distribution are considered. The optimum and nonoptimum stress releasing processes are discussed. The problem of threading dislocation density diminution with generation of the intersecting MDs having the same Burger's vector (L-shaped MDs) is considered for (001) and (111) interfaces. It is shown that such MDs can be effectively generated only at the initial stage of the releasing process, since generating is accompanied by the increase in the level of long-range shear stresses.