MICROSTRUCTURE OF MULTILAYER HETEROSYSTEMS CONTAINING MOLECULES OF Ge QUANTUM DOTS IN Si ON THE STAGES OF NUCLEATION AND GROWTH BY EXAFS SPECTROSCOPY
S. B. Erenburg1,2, S. V. Trubina1, V. V. Zvereva1, V. A. Zinov’ev3, A. V. Dvurechenskiy3, P. A. Kuchinskaya3, K. A. Kvashnina4,5
1Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
3Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
4ESRF, Grenoble, France
5HZDR, Institute of Resource Ecology, Dresden, Germany
Keywords: микроструктура, полупроводниковые гетеросистемы, молекулы из квантовых точек GeSi, спектры EXAFS, microstructure, semiconductor heterosystem, molecules of quantum dots GeSi, EXAFS spectra
Abstract
Ge K-edge EXAFS (Extended X-Ray Absorption Fine Structure) spectra have been measured for multilayer semiconducting heterosystems containing interacted groups of quantum dots ("molecules from quantum dots") ordered in rings on different stages of their growth depending on topologic parameters and growth conditions. In accordance with our results obtained previously for the quantum dots of SiGe, for the molecules of quantum dots it was found that deformation at the interface leads to decrease in the interatomic distance of Ge-Ge by ~0.03 Å. Effect of heterosystem topology and temperature at different stages of their growth on interlayer diffusion was investigated. It was found that at the first growth stage (growth of "seeded islands" serving as a basis for obtaining the molecules) at 700°C a concentration of Ge atoms in the system is ~38%. With further growth of the vertically-matched quantum dots groups the concentration of Ge increases up to ~43-47% depending on the growth conditions. Comparable analysis of different modes of EXAFS measurements was performed to determine precisely structural parameters of heterosystem SiGe with different thickness grown on Si(100) surface.
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