Thin amorphous films which had been grown on Si were studied by using the near-edge X-ray absorption fine structure technique. The N dangling bonds in N-rich films gave rise to a strong resonance line, at the onset of the N 1s absorption edge; with an intensity that increased with the N/Si ratio. Further data on the origin of the resonance line were provided by spectra from N-implanted Si and Si3N4 films which were bombarded with Ar ions. The resonance lines could be removed by annealing at temperatures which were higher than the growth temperature. It was suggested that the annealing of the resonance line was due to the formation of Si-N bonds, where the Si atoms were provided by the stressed interface. The velocity of the annealing process was controlled by the diffusion of Si interstitials in the nitride, and the process was characterized by an activation energy of 0.86eV.

E.C.Paloura, A.Knop, K.Holldack, U.Döbler, S.Logothetidis: Journal of Applied Physics, 1993, 73[6], 2995-3000