Skip to Main Content
A one-dimensional (1-D) fluid model is developed for an RF acetylene discharge. In total, 24 species (neutrals, radicals, electrons, and ions) are considered. For every species, a mass balance equation is solved. Further, the electron energy equation and the Poisson equation are also considered. Reactions taken into account include 19 electron-neutral, one ion-neutral, and 17 neutral-neutral reactions. The reaction rate coefficients of the ion-neutral and neutral-neutral reactions are taken from literature. The rate coefficients of the electron-neutral reactions depend strongly on the average electron energy, and are, therefore, obtained from a simplified Boltzmann equation. The 1-D fluid model yields, among others, information about the densities of the different species in the plasma. The most important neutral species in an acetylene plasma are C2H2 and H2. Further, the radicals C4H2, C6H2, and C8H2 (to a minor extent) are also present at high densities. These higher order carbon radicals are mainly formed in neutral-neutral reactions with C2H. Other radical species present at high densities are H, C2H3, CH2, and CxH (with x equal to 2, 4, and 6). The most important ionic species are found to be C4H2+, C2H2+, and C6H2+. Finally, a comparison is made between an acetylene and a methane plasma.