Oxygen-assisted control of surface morphology in nonepitaxial sputter growth of Ag

Abstract

The surface roughness of Ag films (thickness of 50nm) is drastically reduced from 2.4to1.0nm by the presence of oxygen (pressure of 2×10−5mbar) during sputter growth, without a change (undermining) in electrical transport properties nor a formation of any Ag oxide phase. It is concluded that oxygen plays the role of a surfactant. The growth scenario (nonepitaxial sputter deposition of relatively thick films) makes this observation complementary to previous studies reporting surfactant effects in epitaxial growth of Ag. The authors consider an application of this finding in the field of multilayers involving Ag metals.