Measurement of the dielectric constant of amorphous CNx films in the 0-45 eV energy range

Amorphous a-CNx thin films were deposited at room temperature by pulsed las er ablation of graphite targets in a controlled nitrogen atmosphere. By mea ns of reflection electron-energy-loss spectroscopy their dielectric functio n has been obtained in the 0-45 eV energy range. An appropriate method of a nalysis has been also proposed which does not take into account surface con tributions to the measured spectra in the presence of large electron inelas tic mean free paths. The overall results show that the-nitrogen introductio n in the amorphous carbon matrix induces an increase in the total threefold coordination, i.e., a progressive material graphitization. This finding is also confirmed from x-ray photoelectron spectroscopy results for the N and C Is core levels.