The Young's modulus of chromium nitride films

The Young's modulus of chromium nitride (CrN) films usually determined by complex and a destructive technique was obtained by conducting conventional X-ray diffraction and stress measurements. The CrN films were deposited onto (100) Si substrates by cathodic arc plasma deposition and then annealed in a N2/H2=9 reducing atmosphere between 300 and 900 °C. X-Ray diffraction spectra revealed that the CrN main (220) peak was shifted from lower diffraction angles toward higher diffraction angles and then back to the standard reference angle with increasing temperature. Strains of the films were calculated from the corresponding interplanar spacing change associated with the peak shift. Residual stresses were determined by the curvature changes resulted from the annealing-induced stress relaxation. The Young's modulus of CrN films was then deduced from the linear relation of stresses and strains by considering residual stresses as plane stresses. The obtained value, 190±50 GPa, is comparable with those reported in the literature.