Influence of non-polymerizable gases added during plasma polymerization

In plasma polymerization often additional, non-polymerizable gases are used, either as carrier gas or as reactive co-monomer. The gas ratio represents an additional parameter, which complicates the understanding of plasma polymerization process. Therefore, we thoroughly investigated the deposition rates of different gas mixtures (O-2/HMDSO, N-2 and NH3/CxHy as well as inert gas/CxHy) on the basis of a macroscopic approach. Since the mass deposition rates depend on the specific energy W/F, the plasma polymerization regime fro the corresponding polymerizable monomer can be identified by introduction of a modified flow F = F-m + aF(c) (sum of monomer flow F-m and carrier gas flow F-c with a flow factor a). Any deviations discovered during application of this novel approach indicate additional effects, such as ion-induced effects.