Dislocation patterning and nanostructure engineering in compositionally graded [formula omitted] layer systems

Abstract

Dislocation morphologies in compositionally graded Si 1 − x Ge x epilayers grown on (001) Si substrates at low temperatures were studied by a combination of experimental techniques sensitive to the plastic activity at different length scales. We demonstrate that strain relief in the thick metastable layers is provided by ordered dislocation configurations composed of narrow slip bands. These configurations are consistent with the dislocation morphologies predicted by the model of self-adjustment of misfit dislocations. It is shown that crystallographic slip of misfit dislocations in these layers can be used as a basis for a new and straightforward technique for the spatial patterning of semiconductor material on large areas at the nanometer length scale.