GeSi/Si heterostructures consisting of a plastically relaxed layer that included various fractions of Ge and which was grown on Si(001) span the values of the lattice parameter from equal to that in Si to equal to that in Ge. The corresponding substrates were conventionally referred to as artificial. A number of methods exist for growing high-quality GeSi layers with as large as 100% of Ge on Si(001) substrates through an intermediate GeSi layer with a varying composition. However, it was desirable in a number of cases to have ultra-thin (< 1μm) GeSi and Ge layers directly on the Si(001) substrate for practical applications. The results of new methods such as the use of a buffer Si layer grown at a comparatively low temperature (300 to 400C) in plastic relaxation of the GeSi/Si(001) heterostructures and also the use of surfactants (Sb and H) were analyzed. The examples of artificial introduction of centres for origination of misfit dislocations as an alternative to their introduction from the rough surface were considered. It could be concluded that, in order to expand the range of potentialities of growing perfect plastically relaxed GeSi(001) films, it was necessary to make it possible to form in a controlled manner the centres for origination of the misfit dislocations and retard or completely suppress the transition of the growth mechanism from 2- to 3-dimensional in order to prevent the formation of additional misfit dislocations from the surface of the stressed film and, correspondingly, additional threading dislocations.

Potentialities and Basic Principles of Controlling the Plastic Relaxation of GeSi/Si and Ge/Si Films with Stepwise Variation in the Composition. Y.B.Bolkhovityanov, A.K.Gutakovskii, A.S.Deryabin, O.P.Pchelyakov, L.V.Sokolov: Semiconductors, 2008, 42[1], 1-20