Nucleation and growth of hydrogenated microcrystalline silicon films : new insights from scanning probe microscopies

For mixed-phase films prepared by plasma enhanced chemical vapour deposition the density of crystallites in an amorphous matrix was measured as a function of the hydrogen-dilution of the source gas. General features of the observed growth mode can be described in terms of a genuine surface model incorporating autocatalytic crystallization. We investigated the chemical transport of silicon-related species in a hydrogen plasma and found it to be of major importance under the present conditions. The results cast some doubts on previous concepts relating to the existence of a growth zone and of amorphous incubation layers as observed by in-situ ellipsometry