SiO2/Si interface structure and its formation studied by large-scale molecular dynamics simulation

Takanobu Watanabe, K. Tatsumura, I. Ohdomari

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    Abstract

    We investigated the atomic structure of the SiO2/Si interface and the initial oxidation process of Si surfaces using our developed large-scale atomistic simulation technique for Si, O mixed systems. We constructed large-scale SiO2/Si(001) interface models (now up to 12,536 atoms in size) by inserting O atoms into Si-Si bonds in crystalline Si substrates from the surface of the models. The resulting SiO2/Si models exhibited a compressively strained oxide region near the interface, and reproduced X-ray diffraction peaks compatible with experimental results. Using the large-scale modeling technique, we simulated an atomistic oxidation process where the O atoms were introduced into the Si substrate in one by one so as to minimize the strain energy caused by the insertion of the O atoms. A mostly abrupt change in the composition at the SiO2/Si interface was reproduced in this energetic scheme, though the oxidation did not proceed layer by layer as previously reported by many other reports. We found out that the layer-by-layer oxidation phenomenon can be explained by the kinetics of oxidants arriving at the interface through the oxide film.

    Original languageEnglish
    Pages (from-to)125-133
    Number of pages9
    JournalApplied Surface Science
    Volume237
    Issue number1-4
    DOIs
    Publication statusPublished - 2004 Oct 15

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    Keywords

    • Molecular dynamics simulation
    • SiO/Si
    • X-ray diffraction

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Surfaces, Coatings and Films
    • Condensed Matter Physics

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