Electron transport coefficients in mixtures of CF₄ and CF ₂ radicals

Electron kinetics determines the rate of production of chemically active species in processing plasmas. Precise transport coefficients are needed to describe conditions such as those found in plasma assisted technologies for semiconductor production, but these are affected by the density of free radicals, which in themselves depend on the chemical kinetics. We present transport coefficients for electrons in mixtures of CF₄ with CF ₂ (and we also show similar results for other radicals) for ratios of the electric field to the gas number density E/N from 1 to 1000 Td (1 Td = 10^-21 V m²). Our analysis of non-conservative collisions revealed a range of E/N where electron attachment to radicals significantly changes the electron kinetics compared with pure CF₄ gas. The results are obtained using simple solutions for Boltzmann's equation and exact Monte Carlo simulations.