cUniversity of Crete, Physics Department and Foundation for Research and Technology-Hellas (FORTH), Laser and Application Division P.O.Box 1527, 71110 Heraklion, Crete, Greece.

Carbon nitride thin films deposited by different techniques show characteristics that are still far from the ones predicted by Liu and Cohen for the b -C₃N₄ phase. We have tried to prepare CN_x films, for the first time, by reactive ultra-short excimer laser ablation (KrF, l =248 nm, t =0.5 ps) of graphite at 9 and 25 J/cm² laser fluences in different nitrogen pressures. In this paper we report the results of the characterizations (scanning electron microscopy, X-ray diffraction, Rutherford backscattering spectroscopy) performed on our films. Moreover UV-VIS spectroscopy let us to determine the optical properties of the synthetized material, while Fourier transform infrared absorption spectroscopy and Raman scattering spectroscopy in the visible range let us to distinguish between different bonding types and domains size and to study disorder in the grown films. Finally, the very low N/C atomic ratios of the present films will be discussed and compared to the ones of the films deposition by reactive nanosecond laser ablation.