Surface geometry of MBE-grown GaAs(001) surface phases

Qikun Xue, T. Hashizume, T. Sakata, Y. Hasegawa, A. Ichimiya, T. Ohno, T. Sakurai

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    11 Citations (Scopus)


    The MBE-grown GaAs(001) surface exhibits various surface phases depending on the surface temperature and As/Ga flux ratio during the growth. Using scanning tunneling microscopy, reflection high energy electron diffraction and theoretical simulations, we have carried out a systematic study of various phases from As-rich c(4 × 4), 2 × 4 to Ga-rich 4 × 2 and 4 × 6, utilizing migration-enhanced epitaxy. Based on our thorough investigation, we were able to propose a simple and unified structural model for the evolution of surface phases. The As-rich 2 × 4 phase consists of two As dimers on the top layer and another As dimer on the third layer (Chadi's two-dimer model), while there is still a small window where a slightly As-poor phase may exist consisting of two As dimers on the top layer and second layer relaxation (Northrup-Froyen model). As for the Ga-rich 4 × 2, we determined that the Beigelsen's two-Ga-dimer model fits best to our experimental and theoretical results, which consists of two Ga dimers on the top layer and an additional Ga dimer on the third layer, a mirror image of Chadi's two-dimer model for the As-rich 2 × 4 phase. Our direct observations reveal that there are two distinct 4 × 6 phases.

    Original languageEnglish
    Pages (from-to)556-561
    Number of pages6
    JournalThin Solid Films
    Issue number1-2
    Publication statusPublished - 1996 Aug 1


    • Gallium arsenide
    • Molecular beam epitaxy
    • Surface geometry

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Surfaces and Interfaces
    • Surfaces, Coatings and Films
    • Metals and Alloys
    • Materials Chemistry


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