Two-Dimensional interfaces may not be flat

ORAL

Abstract

The interfaces between two-dimensional (2D) materials and 2D-3D materials host rich and diverse phenomena and applications. However, most studies only show a rather local picture of these interfaces. The understanding of the interface interaction including interface flatness on a larger scale remains limited. Here we present the flatness of 2D-2D and 2D-3D interfaces in arrays of field-effect transistors with a total length of over 16 µm. This approach shows a more complete picture of the 2D interfaces from multiple metal contacts and transistor channels, with and without hexagonal boron nitride (hBN) encapsulation. By using cross-sectional transmission electron microscopy (TEM), we observe that transferring hBN onto contacted 2D materials can dramatically alter the interface structure. Intriguingly, the interface between 3D metal and 2D materials is also not flat. We observe highly non-uniform adhesion between evaporated metal on 2D materials. Finally, we correlate the interface characterization with electrical device measurements, highlighting that interface dynamics can profoundly impact device operation in transistors and beyond. Our results reveal the intricacy and complexity of 2D interfaces and challenge the conventional assumption that 2D interfaces are always flat and uniform.

*Z.C. acknowledges financial support from Semiconductor Research Corporation (SRC) nCORE program sponsored by NIST through award number 70NANB17H041. A.D.F acknowledges the support from the National Science Foundation under Grant ECCS 1915814. H.Z. acknowledges support from the U.S. Department of Commerce, NIST under financial assistance award 70NANB19H138. A.V.D. acknowledges support from the Material Genome Initiative funding allocated to NIST.

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Presenters

  • Zhihui Cheng

    • National Institute of Standards and Technology & Purdue University

Authors

  • Zhihui Cheng

    • National Institute of Standards and Technology & Purdue University

  • Huairuo Zhang

    • National Institute of Standards and Technology

  • Son T Le

    • National Institute of Standards and Tech
    • Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD USA and Theiss Research, La Jolla, CA USA

  • Hattan Abuzaid

    • Duke University, Department of Electrical & Computer Engineering

  • Guoqing Li

    • North Carolina State University, Department of Materials Science and Engineering

  • Yifei Yu

    • North Carolina State University, Department of Materials Science and Engineering

  • Albert Davydov

    • Materials Science and Engineering Division, National Institute of Science and Technology
    • National Institute of Standards and Technology
    • Materials Science and Engineering Division - National Institute of Standards and Technology

  • Linyou Cao

    • North Carolina State University, Department of Materials Science and Engineering

  • Aaron D Franklin

    • Duke University, Electrical & Computer Engineering and Chemistry

  • Curt A Richter

    • National Institute of Standards and Tech
    • Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD USA
    • National Institute of Standards and Technology