Paper PS-MoA8
Ion-Surface Interactions Beyond Etching

Monday, October 20, 2008, 4:20 pm, Room 304

Plasma etching has been conceptually distinguished into physical and chemical etching, in reference to the way material is removed from the surface under ion bombardment. There are other ion-surface interactions at play, which have received little attention although they may substantially alter the outcome of the etching process—especially when patterning wafers. We will present evidence from ion beam experiments for the following mechanisms: 1) Eley-Rideal (abstraction) reactions, 2) Electronic excitation as a result of inelastic collisions, 3) Pre-dissociation of molecular ions before collision with the surface, and 4) Coulomb explosion of adsorbed electronegative atoms. The importance of these processes in plasma etching will be discussed.