Construction and validation of C3F8 electron impact and heavy particle reaction scheme for modeling plasma discharges

Abstract

This work presents the results of developing a set of electronic and chemical reactions for a plasma discharge in octafluoropropane (C3F8). Electronic reactions were obtained using the most relevant set of cross sections at the moment, taking into account experimentally known dissociation and ionization channels. Based on the dissociation products obtained during electronic reactions, a set of chemical reactions was adapted by analogy with the C4F8 reaction scheme from the literature. Next, the resulting complete set of reactions was tested against published experimental data on the concentration of electrons, negative ions, and electronegativity in a capacitive plasma discharge at different gas pressures and discharge input powers. For this purpose, a one-dimensional hydrodynamic drift-diffusion model was used. Reasonable agreement was obtained between the model and experimental data on electronegativity. Eventually, the resulting set of reactions was adapted for a two-dimensional hydrodynamic drift-diffusion model of an ICP discharge. The results of the calculations are two-dimensional distributions of radicals and ions, radical and ion composition of fluxes onto the substrate under conditions typical for industrial reactors.