DEFECTS AND STRESS-ANALYSIS OF THE RAMAN-SPECTRUM OF DIAMOND FILMS

Diamond films were deposited on silicon substrates at 750 °C, by the hot-filament technique, from a reactive CH4 (0.1-2%) H2 mixtures. Two wide Gaussian lines around 1330 and 1500 cm-1 with coupled variations in the whole preparation range appeared in the global Raman spectra. They were attributed to intermediate carbon defects in the diamond crystallites, which might control the confinement length of diamond phonons. Their contributions to the diamond line shift and width for all the samples is calculated and compared with the experimental results. The remaining shift is attributed to the stress (up to 1.2 GPa), while the origin of the remaining widening (large distribution of stress or Raman inactive additional defects) is discussed. © 1992.