Variation of the discharge characteristics with the ion mass in a capacitive coupled RF plasma

The properties of the particle flux in a multiple species plasma at the sheath boundary for both collisionless and collisional discharges is investigated through a computational experiment using the kinetic particle-in-cell code OOPIC Pro. A knowledge of the ion fluxes at the sheath entrance can be utilized in many systems including the determination of the plasma properties from Langmuir probe data and the calculation of surface quantities that depend on the ion flux such as the sputtering yield. It is shown that the different ion masses influence the relative concentrations of each species and play an important role in determining the velocity ratios using two-component mixtures of hydrogen, helium and argon.