First and second-order Raman analysis on annealed silicon nitride films is reported. Possible formation of amorphous Si nanoparticles after an intermediate treatment is deduced from the occurrence of a resonant spectrum. After nucleation of Si nanocrystals, with a model description of the first-order spectra it is possible to access information regarding mean radius, size dispersion, and crystalline phase fraction consistent with the fundamental data derived from microscopy. Substantial increase in second to first order intensity ratio is also observed: Enhanced electron–phonon coupling in both amorphous and crystalline Si nanoparticles is suggested.