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

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


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.

Publication forum classification

Field of science, Statistics Finland