Stress-driven self-ordering of III–V nanostructures

Abstract

We report lateral orderings of III–V nanostructures by the stress field of a periodic dislocation network (DN) shallowly buried and parallel to the surface. These nanostructures consist of thickness modulations of GaAs and InGaAs layers grown by metalorganic vapor-phase epitaxy. We study here two samples for which the growth was performed at two different temperatures. The DNs of these two samples are composed of a one-dimensional network of mixed dislocations and of a one-dimensional network of screw dislocations. These DNs are grain boundaries which form, between a thin GaAs layer and a GaAs substrate joined together by wafer bonding, in order to accommodate a tilt and a twist between these two crystals. Both these misorientations are imposed in a controlled manner. The dimensions and orientation of the nanostructures formed at the surfaces of the samples are identical to those of the cells defined by the underlying DNs. Moreover, we demonstrate that by reducing the growth temperature, we favor the formation of less flat nanostructures which approach the aspect of conventional quantum dots.