Energetic particles in PVD technology: particle-surface interaction processes and energy-particle relationships in thin film deposition

Abstract

Energetic deposition techniques, including ion beam assisted deposition, ion plating, unbalanced magnetron sputtering, and cathodic-arc deposition, are playing an increasing role in the processing of coatings for mechanical, optical, and electronic applications, and for the protection of surfaces in hostile environments. Advantages of energetic film deposition include low temperature processing, improved adhesion to substrates, production of desired phases or compounds, and control of crystallographic orientation. There are certain fundamental physical processes common to these energetic deposition methods that involve the alloying of elements (ion implantation, condensate and gas adsorption), material removal (sputtering, desorption), collision-induced displacements, collision-stimulated thermal exchange, and collision-induced surface and bulk diffusion. The mechanisms by which these mechanisms affect film formation are under intense investigation. New Monte Carlo and molecular dynamics simulations of the effects of energetic atoms on surfaces as well as experimental investigations revealing relationships between deposition variables and phase formation are contributing to our understanding of thin film growth. This paper covers the above topics by first establishing the ‘ideal’ conditions for deposition of a film, indicates how different deposition processes attempt to approximate these conditions, and reviews known correlations between deposition variables and film characteristics.