RF-plasma assisted pulsed laser deposition of carbon films from graphite target

The increasing interest on electron emission properties of thin carbon films with different percentages of sp(3) and sp(2) configurations, and/or with different space domain or dimension of carbon clusters, stimulated a lot of research activities also in the preparation methods, more suitable to deposit thin films with optimised electronic characteristics. The aim of our work is to explore the possibility of depositing films, by pulsed laser deposition (PLD) (Nd:YAG, lambda = 532 nm), with controlled percentage of sp(3)/sp(2) carbon component or even with nanoscopic structure, introducing an ancillary energy source, coming from the presence of plasma-activated species, obtained by a radio frequency system, in the proximity of the substrate. The results obtained by the plasma activated PLD method are compared with those obtained by a plain PLD, working under the same experimental conditions (fluence, pressure, inert buffer gases). The substrate temperature was varied from room temperature up to similar to750 degreesC, to ascertain its influence on the microstructure evolution. Micro-Raman spectra show significant variations as a function of substrate temperature and RF-plasma activation. The results are correlated with surface morphology modifications followed by SEM spectroscopy.