Raman scattering and x-ray absorption studies of Ge-Si nanocrystallization

A. Kolobov, H. Oyanagi, N. Usami, S. Tokumitsu, T. Hattori, S. Yamasaki, K. Tanaka, S. Ohtake, Y. Shiraki

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    26 Citations (Scopus)

    Abstract

    We have studied the local structure of GeSi nanocrystals embedded in SiO2 prepared by co-sputtering of Ge, Si, and SiO2 targets onto a Si(100) substrate. From Raman scattering, we conclude that the formation of the isotropic crystalline Ge phase starts at about 800°C followed by the formation of a GeSi phase at higher temperatures. The formed nanocrystals, whose size depends on the annealing temperature, are randomly oriented. The local structure of the nanocrystals has been studied by x-ray absorption fine structure spectroscopy. They are found to consist of a relaxed Ge core with a typical diameter of ∼4 nm and the Ge-Ge bond length of 2.45 Å and of a GeSi outer shell, the Ge-Si bond length being 2.39 Å. The average composition of the grown nanocrystals is estimated to be Ge 0.75Si0.25.

    Original languageEnglish
    Pages (from-to)488-490
    Number of pages3
    JournalApplied Physics Letters
    Volume80
    Issue number3
    DOIs
    Publication statusPublished - 2002 Jan 21

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

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