Plasma-assisted deposition processes: Theory, mechanisms and applications

Abstract

The energetic electrons in electric discharge plasmas interact effectively with the electron systems of atoms and molecules and thereby impart to these plasmas the same remarkable catalytic properties that characterize the radiation chemistry environment. Plasmas offer the additional important attribute that the energy and flux of active species passing from the plasma volume to an adjacent surface can be controlled to a large extent by controlling the volume chemistry and the electrical potential of the surface relative to the plasma. Accordingly, preferred interactions can be promoted with the surfaces of substrates and growing coatings, and plasmas have come to play a significant role in a range of deposition processes including sputtering, ion plating, activated reactive evaporation and plasma-assisted chemical vapor deposition, etching, polymerization and nitriding. In this paper these applications are reviewed briefly and the analytical modeling of electric discharge plasmas is discussed with emphasis on the principal mechanisms that should be taken into account.