A two-dimensional numerical code, previously developed for the modelling of a-Si:H
deposition in a SiH4/H2 radio frequency cylindrical PECVD reactor, has been modified in
order to perform the modelling of CH4/H2 mixtures in the same experimental configuration.
This model, which includes electrical and chemical modules, takes into account the transport
and the chemistry of the charged and neutral species. The results of the models have been
compared to measurements. The calculated electrical power coupled to the plasma and the
self-bias voltages are compared to the experimental ones. The calculated radical densities are
compared to those measured by threshold ionization mass spectroscopy at the substrate centre.
Moreover, the calculated radial distribution of the deposition rate is compared to profilometry
measurements. Eventually, results obtained here in CH4/H2 are compared with those
previously obtained in SiH4/H2 plasmas under similar experimental conditions.