title: Effective cleaning of hexagonal boron nitride for graphene devices.
abstract: Hexagonal boron nitride (h-BN) films have attracted considerable interest as substrates for graphene. ( Dean, C. R. et al. Nat. Nanotechnol. 2010 , 5 , 722 - 6 ; Wang, H. et al. Electron Device Lett. 2011 , 32 , 1209 - 1211 ; Sanchez-Yamagishi, J. et al. Phys. Rev. Lett. 2012 , 108 , 1 - 5 .) We study the presence of organic contaminants introduced by standard lithography and substrate transfer processing on h-BN films exfoliated on silicon oxide substrates. Exposure to photoresist processing adds a large broad luminescence peak to the Raman spectrum of the h-BN flake. This signal persists through typical furnace annealing recipes (Ar/H(2)). A recipe that successfully removes organic contaminants and results in clean h-BN flakes involves treatment in Ar/O(2) at 500 °C.
authors.affiliation: Department of Applied Physics, McCullough Building, Stanford University, Stanford, California 94305-4045, United States. ag254@stanford.edu
authors.forename: Andrei G F
authors.initials: AG
authors.lastname: Garcia
authors.forename: Michael
authors.initials: M
authors.lastname: Neumann
authors.forename: François
authors.initials: F
authors.lastname: Amet
authors.forename: James R
authors.initials: JR
authors.lastname: Williams
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Taniguchi
authors.forename: David
authors.initials: D
authors.lastname: Goldhaber-Gordon
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D003902:Detergents / Q000737:chemistry*; D004340:Drug Contamination / Q000517:prevention & control*; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size
chemical_list: D001896:Boron Compounds; D003902:Detergents; C017282:boron nitride; D006108:Graphite