Covalent nature in la-silicate gate dielectrics for oxygen vacancy removal

Takamasa Kawanago, Kuniyuki Kakushima, Parhat Ahmet, Kazuo Tsutsui, Akira Nishiyama, Nobuyuki Sugii, Kenji Natori, Takeo Hattori, Hiroshi Iwai

    Research output: Contribution to journalArticle

    2 Citations (Scopus)


    This letter focuses on studying the characteristic behavior of oxygen in La-silicate dielectrics by comparison with HfO 2 dielectrics. V FB shift of La-silicate caused by oxygen annealing is found to be stable even after reduction annealing unlike with HfO 2. Moreover, reduced gate leakage current and improved effective mobility of nMOSFETs with La-silicate are observed by oxygen incorporation, suggesting the annihilation of oxygen vacancy. Since the oxygen in La-silicate covalently exists adjacent to the Si atom, stability of oxygen in La-silicate can be understood in terms of strong bonding of covalent nature.

    Original languageEnglish
    Article number6129473
    Pages (from-to)423-425
    Number of pages3
    JournalIEEE Electron Device Letters
    Issue number3
    Publication statusPublished - 2012 Mar 1


    • Covalent nature
    • HfO
    • La-silicate
    • high-k gate dielectrics
    • ionic nature
    • oxygen vacancy

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Electrical and Electronic Engineering

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  • Cite this

    Kawanago, T., Kakushima, K., Ahmet, P., Tsutsui, K., Nishiyama, A., Sugii, N., Natori, K., Hattori, T., & Iwai, H. (2012). Covalent nature in la-silicate gate dielectrics for oxygen vacancy removal. IEEE Electron Device Letters, 33(3), 423-425. [6129473].