Dislocation formation from one inclined free-surface of a buried layer in a matrix

The introduction of a dislocation from one lateral surface of a two-dimensional buried layer embedded in a matrix has been theoretically investigated in the interfaces between the two materials. It is found that the lower (and longer) interface is a preferential site where the dislocation can be introduced to relieve the misfit strain. For given layer thickness and lattice mismatch between the matrix and the layer phases, a critical angle has been determined beyond which the introduction of the dislocation is energetically favorable. A stability diagram associated with the dislocation formation has been then provided with respect to the misfit strain, inclination angle and layer thickness. The case of a SixGe1−x layer embedded in a Ge matrix is finally discussed.