SIMULATION OF CAPACITIVELY COUPLED RF DISCHARGE IN ARGON

In this work, the axial profiles of the density of electrons and positive ions, the mean electron energy, the electric field strength, and the potential were obtained, both on average over the period and in dynamics. It was shown that argon discharges are dominated by ionization by electrons that gained energy by stochastic heating during the expansion of near-electrode sheaths. This ionization occurs in two pulses during one RF period. At low RF voltage between the electrodes, the role of Ohmic heating of electrons in the electric field in a quasi-neutral plasma increases, but the contribution of stochastic heating remains dominant. The time-averaged plasma potential was found to increase non-linearly with the RF voltage between the electrodes Urf. It is shown that at low Urf values (when the RF voltage approaches the discharge extinction curve), the average potential  can reach Urf due to the axial redistribution of the instantaneous potential in the gap between the electrodes.