Mechanism of misfit dislocation network formation in the heteroepitaxial system GeGaAs (001)

The relaxation of elastic stresses caused by GeGaAs epitaxial system annealing is examined using X-ray topography, transmission electron microscopy, and measurements of system's curvature under layer-by-layer etching. A number of misfit dislocations have identical Burgers vector showing the predominance of the dislocation multiplication mechanism proposed by Hagen and Strunk. The analysis of dislocation reactions for possible Burgers vectors of crossing dislocations shows that necessary conditions for this are b1 = ±b2; b = – b, where b are screw components of the Burgers vectors of crossing dislocations.