Positive and negative dipole layer formation at high-k/SiO2 interfaces simulated by classical molecular dynamics

Kosuke Shimura, Ryota Kunugi, Atsushi Ogura, Shinichi Satoh, Jiayang Fei, Koji Kita, Takanobu Watanabe

    Research output: Contribution to journalArticle

    16 Citations (Scopus)

    Abstract

    We show the electric dipole layer formed at a high-k/SiO2 interface can be explained by the imbalance between the migration of oxygen ions and metal cations across the high-k/SiO2 interface. Classical molecular dynamics (MD) simulations are performed for Al2O3/SiO2, MgO/SiO2, and SrO/SiO2 interfaces. The simulations qualitatively reproduce the experimentally observed flatband voltage (VFB) shifts of these systems. In the case of the Al2O3/SiO2 interface, a dipole layer is formed by the migration of oxygen ions from the Al2O3 side to the SiO2 side. By way of contrast, opposite dipole moments appear at the MgO/SiO2 and SrO/SiO2 interfaces, because of a preferential migration of metal cations from the high-k oxide toward the SiO2 layer in the course of the formation of a stable silicate phase. These results indicate that the migrations of both oxygen ions and metal cations are responsible for the formation of the dipole layer in high-k/SiO2 interfaces.

    Original languageEnglish
    Article number04EB03
    JournalJapanese Journal of Applied Physics
    Volume55
    Issue number4
    DOIs
    Publication statusPublished - 2016 Apr 1

    Fingerprint

    Molecular dynamics
    Positive ions
    dipoles
    molecular dynamics
    Oxygen
    Ions
    oxygen ions
    Metals
    Dipole moment
    cations
    Interfaces (computer)
    Silicates
    metals
    Oxides
    Computer simulation
    Electric potential
    electric dipoles
    silicates
    dipole moments
    simulation

    ASJC Scopus subject areas

    • Engineering(all)
    • Physics and Astronomy(all)

    Cite this

    Positive and negative dipole layer formation at high-k/SiO2 interfaces simulated by classical molecular dynamics. / Shimura, Kosuke; Kunugi, Ryota; Ogura, Atsushi; Satoh, Shinichi; Fei, Jiayang; Kita, Koji; Watanabe, Takanobu.

    In: Japanese Journal of Applied Physics, Vol. 55, No. 4, 04EB03, 01.04.2016.

    Research output: Contribution to journalArticle

    Shimura, Kosuke ; Kunugi, Ryota ; Ogura, Atsushi ; Satoh, Shinichi ; Fei, Jiayang ; Kita, Koji ; Watanabe, Takanobu. / Positive and negative dipole layer formation at high-k/SiO2 interfaces simulated by classical molecular dynamics. In: Japanese Journal of Applied Physics. 2016 ; Vol. 55, No. 4.
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    AU - Kunugi, Ryota

    AU - Ogura, Atsushi

    AU - Satoh, Shinichi

    AU - Fei, Jiayang

    AU - Kita, Koji

    AU - Watanabe, Takanobu

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