Origin of visible photoluminescence from Si-rich and N-rich silicon nitride films

Si-rich (SiN 1.1 ) and N-rich (SiN 1.5 ) silicon nitride films were grown on the Si wafers by plasma-enhanced chemical vapor deposition. Their composition and structure were investigated by Rutherford backscattering spectroscopy and transmission electron microscopy. The effect of composition and post-deposition annealing temperature on the SiN x light-emitting properties was investigated by the examination of photoluminescence. The intensive bands for the Si-rich and N-rich nitride films were detected in the red and blue spectral ranges, respectively. Photoluminescence bands transformations for the annealed nitride films can be ascribed to the increasing K- and N-centre concentration via the Si H and N H bonds rupture and the competitive processes of defect annihilation. On the basis of photoluminescence band FWHM broadening with “ x ” increasing, the FWHM dependence on the measurement temperature and SiN x films inhomogeneous structure, the emission from the SiN 1.1 and SiN 1.5 films is attributed to the transitions between the bands of defect and tail states associated with chemical disordering.