<title>Elastic properties of cBN films by surface Brillouin scattering</title>

Abstract

Surface Brillouin scattering (SBS) has been used to determine the elastic properties of thin hard submicron films cBN deposited on silicon. In case of cBN films, only the Rayleigh mode can be clearly identified in the Brillouin spectra. The elastic properties of the films have been determined by fitting experimental data to theoretical dispersion curves. A Green's function method was used to predict Brillouin scattering spectra of the acoustic excitation at the free surface. Our results demonstrate that the effect of thin hBN interlayer located between cBN film and Si substrate on the velocity of surface acoustic wave (SAW) does not exceed 2% for thin (16 nm film) and is negligible for cBN films thicker than 100 nm. The elastic properties of the cBN films are not softer than those of bulk cBN.