Microstructure of sputtered metal films grown in high and low pressure discharges

Abstract

Sputtered metal films grown in different discharge environments are subject to different degrees of energetic particle bombardment during film growth, resulting in different microstructure and subsequent thin-film properties. The effect on film structure of energetic gas neutrals, backscattered from the sputtering target, together with the role of sputtered neutral metal atoms and those Penning ionized in traversing the plasma, are evaluated in different pressure regimes and under different biasing conditions. It will be shown that the film morphology, degree of texturing, and anisotropic lattice distortions change in a systematic way depending on En, the energy delivered to the growing metal film surface per arriving metal atom. En changes predictably in different discharge pressure regimes as do the resultant film structures and properties. © 1988 American Vacuum Society