Lateral ordering, strain, and morphology evolution of InGaAs/GaAs(001) quantum dots due to high temperature postgrowth annealing

The effect of postgrowth annealing on shape and ordering of a single layer of InGaAs/GaAs(001) quantum dots is investigated by three dimensional grazing incidence small angle x-ray scattering. A transition from disordered dots to two-dimensional lateral ordering is found. This transition is accompanying a quantum dot shape transformation. Grazing incidence diffraction measurements relate the observed ordering type to strain driven self organization. The role of different growth conditions leading to lateral correlation is discussed by comparing the results to recent experimental achievements in the field.