Modified two-dimensional to three-dimensional growth transition process in multistacked self-organized quantum dots

This report proposes ideas that enlighten the modified two-dimensional to three-dimensional transition process in multistacked self-organized quantum dots. Actually, it is shown that the driving force for both the vertical correlation and the reduction of the critical thickness experimentally observed in multistacked self-organized quantum dots does not merely result from the nonuniform strain distribution (induced by the buried dots) as usually accepted, but rather from the elastic interaction between this strain distribution and the strained surface islands. This has been shown by calculating (within continuous elasticity framework) the strain distribution in the case of Ge islands in a Si matrix for which recent experiments are available, but the result applies to other multistacked self-organized quantum dot systems such as InAs/GaAs or InN/GaN.