Elastic constants of sputtered aluminum nitride films

[object Object] Brillouin light scattering has been used for determining the five independent elastic constants of polycrystalline AIN films grown by DC reactive magnetron sputtering on Si,N, coated (100)-Si substrates. The elastic constants cm and cl! have been selectively determined from detection of the shear horizontal mode and of the longitudinal mode travelling parallel to the film surface, respectively. The three remaining elastic constants, namely c13, c33 and c#. have been obtained from detection of the Rayleigh surface mode and of the longitudinal bulk wave propagating at different angles from the surface normal. The values of the elastic constants of these sputtered AlN films exhibit an appreciable dependence on the microstructural properties of the films, which are strongly affected by the deposition conditions. However, they are rather close to those previously determined in epitaxial AIN films grown at high temperature by MOCVD.