Integration of hexagonal boron nitride with quasi-freestanding epitaxial graphene: Toward wafer-scale, high-performance devices

Michael S. Bresnehan, Matthew J. Hollander, Maxwell Wetherington, Michael Labella, Kathleen A. Trumbull, Randal Cavalero, David W. Snyder, Joshua Alexander Robinson

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Abstract

Hexagonal boron nitride (h-BN) is a promising dielectric material for graphene-based electronic devices. Here we investigate the potential of h-BN gate dielectrics, grown by chemical vapor deposition (CVD), for integration with quasi-freestanding epitaxial graphene (QFEG). We discuss the large scale growth of h-BN on copper foil via a catalytic thermal CVD process and the subsequent transfer of h-BN to a 75 mm QFEG wafer. X-ray photoelectron spectroscopy (XPS) measurements confirm the absence of h-BN/graphitic domains and indicate that the film is chemically stable throughout the transfer process, while Raman spectroscopy indicates a 42% relaxation of compressive stress following removal of the copper substrate and subsequent transfer of h-BN to QFEG. Despite stress-induced wrinkling observed in the films, Hall effect measurements show little degradation (<10%) in carrier mobility for h-BN coated QFEG. Temperature dependent Hall measurements indicate little contribution from remote surface optical phonon scattering and suggest that, compared to HfO 2 based dielectrics, h-BN can be an excellent material for preserving electrical transport properties. Graphene transistors utilizing h-BN gates exhibit peak intrinsic cutoff frequencies >30 GHz (2.4× that of HfO 2-based devices).

Original languageEnglish (US)
Pages (from-to)5234-5241
Number of pages8
JournalACS nano
Volume6
Issue number6
DOIs
StatePublished - Jun 26 2012

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All Science Journal Classification (ASJC) codes

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

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