Forming dislocation pairs in the Ge/GeSi/Si(001) heterostructure

In the Ge/LTGe/GeSi/Si(001) heterostructures, the GeSi buffer layer remains pseudomorphic in a certain range of the heterostructure parameters and growth regimes, while the Ge film is completely relaxed owing to the edge dislocation network at the Ge/GeSi interface. It has been experimentally shown that, along with edge dislocations, dislocations with the Burgers vectors of the $a_{0}\langle$001$\rangle$-type form. Their formation is caused by the reaction of 60$^{\circ}$ dislocations with a unidirectional screw component. In this case, if during the buffer layer relaxation the edge dislocations split with the formation of an edge-type dislocation complex, in which the 60$^{\circ}$ dislocations remained bound, the dislocations with the Burgers vectors $a_{0}\langle$001$\rangle$ split into two independent 60$^{\circ}$ dislocations.