Effects of Ion Temperature on Collisionless and Collisional RF Sheath

Abstract

A numerical two-fluid simulation of the non-ionized radio frequency (rf) sheath model, has been carried out. This model is ``global'' and thus applicable to the sheath, pre-sheath and plasma regions, In the model all variables in the ion force balance equation, including the electrical force, ion pressure and neutral particle friction, are considered. The model is solved through a finite difference scheme and sheath characteristics are obtained. The effects of the ion temperature on both the collisionless and collisional sheath characteristics are discussed. Then it is concluded that 1) the model is in a good agreement with Bohm Theorem; 2) the ion temperature has significant effects on the rf sheath characteristics. The effects are far more significant on a collisional rf sheath than on a collisionless sheath.