title: Integration of hexagonal boron nitride with quasi-freestanding epitaxial graphene: toward wafer-scale, high-performance devices.
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).
authors.affiliation: Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Bresnehan
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hollander
authors.forename: Maxwell
authors.initials: M
authors.lastname: Wetherington
authors.forename: Michael
authors.initials: M
authors.lastname: LaBella
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Trumbull
authors.forename: Randal
authors.initials: R
authors.lastname: Cavalero
authors.forename: David W
authors.initials: DW
authors.lastname: Snyder
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Robinson
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D055119:Elastic Modulus; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D060526:Magnetic Fields; D008422:Materials Testing; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D001896:Boron Compounds; D046911:Macromolecular Substances; C017282:boron nitride; D006108:Graphite