Modeling of a capacitively coupled radio-frequency methane plasma: Comparison between a one-dimensional and a two-dimensional fluid model

Abstract

A comparison is made between a one-dimensional ͑1D͒ and a two-dimensional ͑2D͒ self-consistent fluid model for a methane rf plasma, used for the deposition of diamond-like carbon layers. Both fluid models consider the same species ͑i.e., 20 in total; neutrals, radicals, ions, and electrons͒ and the same electron-neutral, ion-neutral, and neutral-neutral reactions. The reaction rate coefficients of the different electron-neutral reactions depend strongly on the average electron energy, and are obtained from the simplified Boltzmann equation. All simulations are limited to the alpha regime, hence secondary electrons are not taken into account. Whereas the 1D fluid model considers only the distance between the electrodes ͑axial direction͒, the 2D fluid model takes into account the axial as well as the radial directions ͑i.e., distance between the electrodes and the radius of the plasma reactor, respectively͒. The calculation results ͑species densities and species fluxes towards the electrodes͒ obtained with the 1D and 2D fluid model are in relatively good agreement. However, the 2D fluid model can give additional information on the fluxes towards the electrodes, as a function of electrode radius. It is found that the fluxes of the plasma species towards both electrodes show a nonuniform profile, as a function of electrode radius. This will have an effect on the uniformity of the deposited layer.

Reaction pathways of producing and losing particles in atmospheric pressure methane nanosecond pulsed needle-plane discharge plasma

“…15 In addition, the comprehensive two-dimensional fluid models have been successfully developed to numerically study CH 4 reforming. [26][27][28] Herrebout et al have compared a one-dimensional and a two-dimensional self-consistent fluid models for the CH 4 radio frequency plasma and have shown that the calculation results obtained with the two models are in relatively good agreement. 26 Babaeva et al have used the twodimensional simulator to research the interaction between plasma filaments in DBDs and liquid covered wounds.…”

“…[26][27][28] Herrebout et al have compared a one-dimensional and a two-dimensional self-consistent fluid models for the CH 4 radio frequency plasma and have shown that the calculation results obtained with the two models are in relatively good agreement. 26 Babaeva et al have used the twodimensional simulator to research the interaction between plasma filaments in DBDs and liquid covered wounds. 27 Levko et al have studied non-thermal plasma ethanol reforming in argon bubbles immersed in liquids using a two-dimensional multi-species fluid model and have analyzed the main reactions responsible for the generation of molecular hydrogen and light hydrocarbon species.…”

Investigating the plasma chemistry for the synthesis of carbon nanotubes/nanofibres in an inductively coupled plasma enhanced CVD system: the effect of different gas mixtures

“…The details are listed in Tables 3-6. Besides the inlet gas (CH 4 /H 2 ), some higher order neutral molecules (C 3 H 8 , C 2 H 6, C 2 H 4, C 2 H 2 ) are also included in our model, because they were found to be formed in the plasma at high densities [44]. Some radical and ionic species (e.g.…”

“…where i in Å 3 is the polarizability of the background gas and is taken from [44] and [47] for all ions. The overall ion mobility µ j of ion j in the gas mixture can again be obtained by Blanc's law; see above.…”

“…All data needed to calculate the diffusion coefficients of all the plasma species included in the models were adopted from [44] and [47]. For ions both motilities and diffusion coefficients are considered.…”