Near-edge x-ray absorption fine structure measurements at the N-K edge are used to monitor the evolution of defect-related structure in the spectra of buried SiNx films as a function of the implantation dose. The buried SiNx films were fabricated with implantation of 35 keV 14N+ ions in Si in the dose range 2×1017–2×1018 cm-2. The defect-related resonances RL1 and RL2 appear at 401.1±0.3 and 403.3±0.1 eV, respectively. The RL1 is characteristic of a defect structure in the low and intermediate implantation doses and can be annealed out with an activation energy of 0.5 eV. RL2, which is the signature of excess N in N-rich films and is attributed to transitions of 1s-electrons to unfilled states with p component at a defect site containing a N dangling bond, can be annealed out only after prolonged annealing at 1150 °C. © 1997 American Institute of Physics.