Electron Collision Cross Sections for the BF3 Molecule and Electron Transport Coefficients in BF3-Ar and BF3-SiH4 Mixtures

Abstract

A consistent set of low-energy electron collision cross sections for the boron trifluoride (BF3) molecule has been derived from the measured electron transport coefficients for a pure BF3 molecule using an electron swarm study and a two-term approximation of the Boltzmann equation for energy. The electron transport coefficients, which were calculated using the derived set, are consistent with the experimental data over a wide range of E/N values (ratio of the electric field E to the neutral number density N). The present set of electron collision cross sections for the BF3 molecule, therefore, is the best available so far for the quantitative numerical modeling of plasma discharges for processing procedures with materials containing BF3 molecules. The electron-transport coefficients for BF3-Ar and BF3-SiH4 mixtures were also calculated and analyzed in a wide range of E/N ratios for the first time. The presence of a remarkable synergism in the Townsend first ionization coefficient has been pointed out in BF3-SiH4 mixtures.