Improvement of the thermal stability of amorphous carbon films by incorporation of nitrogen

Nitrogenated amorphous carbon films have been deposited by dual-facing-target sputtering, and their thermal stability has been investigated by means of X-ray diffraction (XRD), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). The XRD analyses indicate a slower graphitization process in the CN films during annealing in comparison with the amorphous C films. The Raman measurements show that the sp 2 concentration increases through nitrogen incorporation, which in turns leads to a smaller layer expansion after annealing. Conductivity measurements further confirm this suggestion. The XPS results give the information of the existence of the strong covalent bonding between N and C atoms, which can slow down the tendency of the structural relaxation during annealing. The effect of nitrogenation on the formation of sp 3 bond is discussed tentatively in terms of coordination. These results suggest that the thermal stability of amorphous C films can be improved by N incorporation through reactive dual-facing-target sputtering.