Abstract
Diamond-like carbon (DLC) thin film deposition was examined by applying 13.56 MHz of r.f. power to the substrate electrode. We tried to control deposition temperature by the plasma pulse deposition technique: repeated cycles of alternating 5 s of deposition with 180 s of cooling, then we investigated the influence of the deposition temperature on the thin film characteristics and structure in details.
It is found that the deposition temperature plays a more significant role than the self-bias potential which is up to now considered as an important parameter. Our results suggest that the surface structure of the film after ion impacted rather than ion impact energies dominates the characteristics and structure determination. Definitely, the deposition temperature is closely related to the mobility of the fragments generated by the ion bombardments and the migration of radical and neutral species adsorbed on the film surface. Moreover, the deposition temperature is concerned in the promotion of the dehydrogenation of the film.
As the model for DLC film structure, we suppose that the three dimensional random network structure is developed mainly, and the condensed aromatic ring structures as precursors of the carbon cluster and the small graphite-like carbon clusters are slightly mixed into the random network structure.
