SEM and Raman investigation of RF plasma assisted pulsed laser deposited carbon films

Thin carbon films with different percentages of sp3 and sp2 configurations, obtained by different deposition methods, have been proved to have electron emission properties, when submitted to high electric fields. The field emission properties seem to be associated with the presence of conductive nano-structured graphite particles embedded in an insulating amorphous carbon matrix. A general feature of these films is the presence of well-separated Raman peaks at 1350 and 1580 cm−1. The aim of our research is to evaluate the influence of an ancillary radio frequency energy source, on the structure of carbon films, obtained by a graphite target ablation. The plasma activated method is compared to traditional pulsed laser deposition (PLD) (Nd:YAG, λ=532 nm), working under the same experimental conditions, optimised to obtain nanoparticle deposition. The substrate temperature varied from room temperature (RT) up to 1000 K, to evaluate the influence of thermal energy on the cluster condensation. The structure of the films grown at different conditions has been examined by scanning electron microscopy (SEM) analysis to determine the occurrence of nano-structured compounds. This information has been correlated to the data on film quality obtained by micro-Raman analysis.