Strain-induced self-organized growth of nanostructures: From step bunchingto ordering in quantum dot superlattices

We have investigated the lateral ordering of dot positions in a SiGe/Si mul tilayer and, for comparison, in a PbSe/PbEuTe dot superlattice using grazin g incidence small-angle scattering. The two samples represent two different approaches to achieve an enhanced ordering of dot positions in semiconduct or heterostructures: in the SiGe/Si sample, step bunching in the multilayer grown on a vicinal Si substrate was exploited to reduce the fluctuations i n lateral dot distances. In the PbSe/PbEuTe sample the strong elastic aniso tropy leads to the formation of a three-dimensional dot "lattice," exhibiti ng a very narrow distribution of dot distances. (C) 2000 American Vacuum So ciety. [S0734-211X(00)00404-2].