Applied Surface Science, Vol.255, No.15, 7104-7108, 2009
Diamond-like phase formation in an amorphous carbon films prepared by periodic pulsed laser deposition and laser irradiation method
Diamond-like carbon (DLC) films were fabricated by pulsed laser ablation of a liquid target. During deposition process the growing. films were exited by a laser beam irradiation. The. films were deposited onto the fused silica using 248 nm KrF eximer laser at room temperature and 10 (3) mbar pressure. Film irradiation was carried out by the same KrF laser operating periodically between the deposition and excitation regimes. Deposited DLC. films were characterized by Raman scattering spectroscopy. The results obtained suggested that laser irradiation intensity has noticeable influence on the structure and hybridization of carbon atoms deposited. For materials deposited at moderate irradiation intensities a very high and sharp peak appeared at 1332 cm (1), characteristic of diamond crystals. At higher irradiation intensities the graphitization of the amorphous. films was observed. Thus, at optimal energy density the individual sp3-hybridized carbon phase was deposited inside the amorphous carbon structure. Surface morphology for DLC has been analyzed using atomic force microscopy (AFM) indicating that more regular diamond cluster formation at optimal additional laser illumination conditions (similar to 20 mJ per impulse) is possible. (C) 2009 Elsevier B. V. All rights reserved.
Keywords:Pulsed laser deposition;Diamond-like carbon;Liquid target;Thin film growth;Raman scattering spectroscopy;DLC