Bonding modifications in carbon nitride films induced by thermal annealing: An x-ray absorption near edge study

The thermal stability of nonstoichiometric carbon nitride films has been st udied by x-ray absorption near edge spectroscopy. Amorphous carbon nitride thin films were annealed in vacuum up to 1150 degrees C revealing the prese nce of nitrogen in different bonding configurations. Annealing to 450 degre es C results in the loss of similar to 50% of the nitrogen. The remaining n itrogen is bonded to carbon within a graphitic framework and it evolves int o a more stable configuration with increasing temperature without significa nt N loss up to 820 degrees C. Beyond this temperature, nitrogen loss occur s without important structural changes. (C) 1999 American Institute of Phys ics. [S0003-6951(99)01918-X].