Radio Frequency Discharge with Dust Particles

Abstract

A 1D PIC/MCC method has been developed for computer simulations of low-pressure RF discharges with dust particles using the method for dust-free discharges. A RF discharge in argon with dust particles distributed uniformly in the interelectrode gap is simulated at parameters providing a possibility to consider the discharge as a physical model of processing plasmas. The spatial distribution of discharge parameters, including a charge of dust particles, across the discharge interelectrode gap has been obtained at various values for the density of the dust particles and for the electric current in the external discharge circuit. The results show that the RF discharge with dust particles has a quasi-neutral central part with a low electric field and non-stationary sheaths with a strong electric field separating the electrodes from the central part. The dust particles essentially influence the spatial distribution of the discharge parameters. In particular, an increase of a dust particle density causes an expansion of sheaths. The electric current in the external electric circuit changes at a sufficiently high density of dust particles. The dust particle charge changes non-monotonously across the interelectrode gap and has a maximum at a sheath edge, due to the spatial distribution of the plasma parameters and a peculiarity of the electron energy distribution function in the quasi-neutral central part of the RF discharge.