The reduction in device structure and interconnect dimensions require more accurate etching procedures. Reactive ion etching provides much of the needed improvements. However, the process can result in damage and contamination effects in the electronic materials used for device fabrication. The damage is mainly due to ion bombardment, ion bombardment in conjunction with coating formation, and/or energetic photons. The contamination effects are because of the residue or surface film formation and etching species or impurity permeation. If the damage and the contamination are not properly controlled or removed they can produce traps and build up charge in oxide, increase junction leakage current, increase contact resistance, degrade carrier lifetime, develop crystal disorder and interfere with subsequent processing. This paper presents an overview of characterization and control of damage, produced by reactive ion etching.