Onset of unstable sheaths and anomalous transverse ion {open_quotes}temperature{close_quotes}

Investigation of sheath structure and ion distribution functions at or near RF and DC conducting boundaries are examined. A self-consistent ion-time-scale 2D and 3D hybrid plasma model is incorporated which solves the relevant subset of Maxwell`s equations fully coupled to the ion Vlasov equation. The treatment evolves from previous steady state 3D plasma edge treatments and from 3D ion-time-scale beam dynamics considerations. One mode of sheath instability identified in the calculations is related to the Bohm sheath criteria. Structure of sheaths and ion distribution functions are studied for several situations relevant to semi-conductor processing, plasma ion implantation, and negative ion extraction. One notable finding is that even near planar boundaries, turbulence may give rise to significant transverse random motion of ions. This may have an impact on anisotropy ratios for semi-conductor processing.