Lateral arrangement of self-assembled quantum dots in an SiGe Si superlattice

Lateral ordering of self-organized quantum dots in a SiGe/Si (001) multilayer has been investigated by grazing incidence x-ray diffraction and Monte Carlo growth simulation. It has been demonstrated that the lateral ordering stems from the elastic anisotropy of the crystal. From the reciprocal space map of the scattered intensity it follows that the dots create a disordered square grid with the axes along [100] and [010]. Both the orientation of the array axes and the mean dot distance have been obtained from the growth simulation.