Morphology and structural characterization of plasma-assisted prepared carbon films

Abstract

Since the properties of amorphous carbon films are determined by the structure of the amorphous network and embedded particles, it is necessary to characterize these properties with respect to the deposition conditions. Relating the particle structure to that of the cathode material may provide information on the origin and growth. The morphology and structure of amorphous carbon films deposited with a pulsed arc source (Laser-Arc) were studied using microscopic (optical, transmission electron microscopy (TEM) and atomic force microscopy (AFM)) and spectroscopic (Raman and electron energy loss spectroscopy (EELS)) investigation methods. The influence of the deposition temperature and annealing after deposition on the structure of the amorphous films was studied. The results of structural analysis show that the homogeneous, very smooth film obtained is amorphous and diamond-like, with a plasmon peak situated at about 28 eV. The influence of the deposition temperature can be seen in the shift of the plasmon peak in the electron energy loss spectrum and the square relation of the fitted D G peak in the Raman spectrum. Particles with dimensions of several hundred nanometres are embedded in the film. In contrast with the film structure, these particles show graphite-like behaviour in the Raman spectrum corresponding to the polycrystalline graphite target material.