Ge/Si Heterostructures with Dense Chains of Stacked Quantum Dots

An overview of new results on growth and characterization of Ge/Si(001) heterostructures with dense chains of stacked Ge quantum dots is reported. Ge hut nucleation and growth at low temperatures is discussed on the basis of results obtained by high resolution scanning tunneling microscopy and in-situ reflected high-energy electron diffraction. Atomic-level models of nucleating and growing huts are considered. Recent data of high resolution transmission electron microscopy are presented focusing on long chains of Ge quantum dots synthesised in silicon matrix by means of molecular beam epitaxy at low-temperature mode. Approaches to formation of three dimensional ordered arrays of Ge cluster and Ge quantum dot crystals are considered in special detail.