Formation of boron‐nitride ultra‐thin films on Si(111)

Abstract

AbstractChemical vapor deposition is employed to form hexagonal boron nitride (h ‐BN) monolayer films on Si(111) with a borazine precursor. The electronic structure and orientation of the films are analyzed by near edge X‐ray absorption fine structure (NEXAFS) spectroscopy and X‐ray photoelectron spectroscopy (XPS). XPS analysis shows that monolayer‐level stoichiometric BN films were formed. The B K‐edge NEXAFS spectra show two discrete peaks that have graphite‐like polarization dependence in the low‐energy region. Polarization dependence analysis of the NEXAFS indicates that the BN films had two‐dimensional orientation on the Si(111) substrate. Based on the density functional theory calculations, these discrete peaks are assigned to π* peaks at an intact h ‐BN site and edge B‐H site. Comparison with the electronic structures of bulk h ‐BN and h ‐BN/Ni(111) clarifies that the interaction between the BN layer and Si substrate was very small. This indicates that the h ‐BN monolayer was physisorbed on Si(111), making a steep interface and conserving the intrinsic electronic structure (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)