Observation of unusual metal-semiconductor interaction and metal-induced gap states at an oxide-semiconductor interface: The case of epitaxial BaO/Ge(100) junction

M. Kuzmin, P. Laukkanen, M. Yasir, J. Mäkelä, M. Tuominen, J. Dahl, M. P. J. Punkkinen, K. Kokko, H. P. Hedman, J. Moon, R. Punkkinen, V. Polojärvi, V. M. Korpijärvi, M. Guina

    Research output: Contribution to journalArticleScientificpeer-review

    8 Citations (Scopus)

    Abstract

    Oxidation of semiconductor surfaces is known to cause defect states at oxide-semiconductor interfaces of various devices. In contrast, effects of the semiconductor interaction with non-oxygen elements at such junctions are still unclear. We present evidence for the interrelationship between a metal (non-oxygen)-semiconductor reaction and formation of the band-gap defect states at a buried oxide-semiconductor interface by investigating well-defined epitaxial BaO/Ge(100) junctions with high-resolution synchrotron-radiation photoelectron spectroscopy. The states that arise from the Ba-Ge interaction lead to Fermi-level pinning at 0.40eV above the valence band maximum, while the defect-free BaO/Ge(100) interface has a flat band structure.

    Original languageEnglish
    Article number165311
    JournalPhysical Review B
    Volume92
    Issue number16
    DOIs
    Publication statusPublished - 20 Oct 2015
    Publication typeA1 Journal article-refereed

    Publication forum classification

    • Publication forum level 2

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Electronic, Optical and Magnetic Materials

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