Spatiotemporal electron dynamics in radio-frequency glow discharges: fluid versus dynamic Monte Carlo simulations

A particle-in cellldynamic Monte Carto simulation technique was developed to study the spatiotemporal electron dynamics in radio-frequency glow discharges. The electric field profile in a parallel plate one-dimensional geometly was obtained from a self-consistent fluid simulation. Using this profile, the particlein-celVdynamic Monte Carto simulation yielded the spatiotemporal electron velocity distribution function between the electrodes. A strongly electronegative chlorine discharge and an electropositive argon discharge were considered. At a pressure of 100 mTorr, the distribution function was non-Maxwellian except at the midgap of the chlorine discharge. The tail of the distribution was strongly modulated inside the sheath. Electron 'pile-ups' near the walls, charge double layers and negative plasma potential during part of the cycle were observed in the electronegative discharge at 13.56 MHz. lime-average results from the particle-in-cell/dynamic Monte Carlo simulation matched the fluid simulation favourably, even at a local Knudsen number Kn % 1, with differences confined mainly to the volume around the plasmahheath interface.