Elastic strain and composition of self-assembled GeSi nanoislands on Si(001)

The growth of self-assembled Ge islands on Si(001) surface and changes in t he island structure parameters in the course of subsequent annealing were s tudied. Island structures possessing a small (similar to 6%) scatter with r espect to lateral dimensions and heights of the islands were obtained. The Raman spectra and X-ray diffraction data show evidence that silicon dissolv es in the islands. The atomic fraction of Si in the resulting SixGe1-x soli d solution was determined and the elastic strain in the islands was measure d. It was found that annealing of the heterostructures with islands is acco mpanied by increasing Si fraction in the islands, which leads to changes in the island shape and size. (C) 2000 MAIK "Nauka/Interperiodica".