Ion- and electron-assisted gas-surface chemistry - An important effect in plasma etching

The extent to which gas-surface chemical reactions can be enhanced by energetic radiation (primarily ions and electrons) incident on the surface is described. Emphasis is placed on chemical systems which lead to volatile reaction products. In particular, the reactions of Si, SiO2, and Si3N4 with XeF2, F2, and Cl 2 are examined experimentally. Possible mechanisms for the radiation-induced enhancement are discussed and some technological implications of this process in plasma etching technology and lithography are considered.