ION KINETICS IN COLLISIONAL RF-GLOW DISCHARGE SHEATHS

Ion kinetic investigations are performed on a 27.12 MHz capacitively coupled parallel plate discharge configuration using argon and oxygen as the process gases. The incident ions on the grounded electrode are separated, according to their mass and energy, and the influence of rf-power density and fetal pressure on the ion mass spectra and, especially, on the ion energy distribution are discussed. In the observed parameter range, a transition from space charge-limited to mobility limited ion transport in the plasma sheath occurs. The ion sheath thickness can be calculated from the change of the shape of the energy distribution with pressure.