Dual-frequency capacitive discharges are used to separately control the mean ion energy, ε- ion, and F flux, ion, at the electrodes. We study the effect of secondary electrons on this separate control in argon discharges driven at 2+27 MHz at different pressures using Particle in Cell simulations. For secondary yield γ≈0, ion decreases as a function of the low frequency voltage amplitude due to the frequency coupling, while it increases at high γ due to the effective multiplication of secondary electrons inside the sheaths. Therefore, separate control is strongly limited. ε- ion increases with γ, which might allow an in situ determination of γ -coefficients.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)