AFM Characterization of Hexagonal Boron Nitride Dielectrics

ORAL

Abstract

Van der Waals heterostructures often rely on electrostatic gating to tune the carrier density in the two-dimensional material of interest. In many cases, large gate voltages are necessary to significantly shift the Fermi level or to apply large displacement fields, which requires ultra-high quality gate dielectrics. In this presentation, we report on using a conductive Atomic Force Microscope (AFM) tip to characterize defects in hexagonal boron nitride (hBN), the primary gate dielectric in van der Waals heterostructures. We initially characterize the hBN flakes by measuring the voltage that must be applied to the AFM tip to break down the hBN dielectric at the point below the tip. Following this procedure, we test whether the breakdown voltage can be improved by electrostatically moving defects using voltage applied to the AFM tip. We present the results of our characterization and defect manipulation to improve hBN dielectric breakdown.

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Presenters

  • Jeffrey Kwan

    • Harvard University

Authors

  • Jeffrey Kwan

    • Harvard University

  • Isabelle Y Phinney

    • Harvard University

  • Andrew Zimmerman

    • Harvard University

  • Zeyu Hao

    • Harvard University

  • James Ehrets

    • Harvard University

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science
    • Kyoto University
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute For Materials Science
    • NIMS
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Philip Kim

    • Harvard University