Monte Carlo-fluid hybrid model of the accumulation of dust particles at sheath edges in radio-frequency discharges

Abstract

Particulate contamination (dust) has been observed to accumulate near the sheath-plasma boundary in both radio-frequency (rf) and direct-current (dc) discharges. We have developed and applied a hybrid Monte Carlo-fluid simulation of electron, ion, and charged dust transport in rf discharges to investigate the dynamics of particulate contamination. The processes governing the transport of charged dust in the model are drift of partially shielded particles in the electric field, collisions with the fill gases, and viscous ion drag arising from Coulomb interactions of particles with ions drifting and diffusing in the plasma. We find that negatively charged dust particles accumulate near the sheath-plasma boundary, and that transport of the particles is dominated by ion drag.