A MODEL FOR PARTICLE GROWTH IN ARC DEPOSITED AMORPHOUS-CARBON FILMS

Are evaporation processes are connected with the emission of small par ticles which are incorporated in the growing film on the substrate. SE M, AFM and optical microscopy indicate a size increase of such objects during film growth. Because of their cone-like shape we call them con e-like nodules. Using conventional measurement methods that can determ ine the structure, it is hard to explain the behaviour and properties of those nodules, as they do not provide clear information about their nature. Square resolved Raman measurements show a mixture of graphiti c and diamond-like structures, that allows to conclude that the nodule consists of a graphitic particle originated at the cathode, covered b y an amorphous carbon film. We propose a new model that describes the growth of cone-like nodules in the homogeneous carbon film very well. It is based on the dependence of the DLC film properties on the incide nce angle of ions. The cone-like shape and the growth behaviour at per pendicular and grazed ion incidence was simulated using a simple compu ter program. A comparison of the simulated data and the SEM-images sho w a good qualitative and quantitative agreement. (C) 1998 Elsevier Sci ence S.A.