Properties of cubic boron nitride films prepared by ion beam assisted deposition

Boron nitride films were prepared by ion beam assisted deposition (IBAD). The films were synthesized on Si[100] substrates by depositing boron vapor under simultaneous bombardment with nitrogen ions and nitrogen-argon mixture ions. Properties of cubic boron nitride (cBN) films are studied especially regarding the crystallization of the films and the valence band spectra obtained from X-ray photoelectron spectroscopy (XPS). Structural analysis by Fourier transform infrared spectroscopy (FTIR) and cross-sectional transmission electron microscopy (TEM) confirms that polycrystalline films with a high cBN fraction were synthesized. Valence-band spectra obtained from XPS were measured to provide a method for characterization of the BN phases on the basis of experimental observations for the bulk cBN and hBN samples and theoretical prediction of densities of states.