Fundamentals of Ion Plating

Abstract

The term ion plating is applied to atomistic film deposition processes in which the substrate is subjected to a flux of high energy ions sufficient to cause appreciable sputtering before and during film formation. From the standpoint of adhesion, the principal benefits obtained from ion plating are (1) ability to sputter clean the surface and maintain it “clean” until the film begins to form; (2) provide a high energy flux to the substrate surface giving a high surface temperature without necessitating bulk heating, thus enhancing diffusion, chemical reaction, etc.; and (3) alter the surface and interfacial structure by introducing high defect concentrations, physically mixing the film and substrate material, and influencing the nucleation and growth of the depositing film. Ion plating is particularly effective in obtaining good adhesion in some systems where conventional deposition techniques give poor results. Another effect found in the ion plating process is the very great “throwing power” of the depositing film material. In this paper the fundamental concepts of ion plating are reviewed along with a discussion of problems peculiar to this deposition process. Several representative applications will be described.