Silver Direct Electrodeposition on Ru Thin Films

Abstract

Electrodeposition of Ag was performed on Ru thin films following electrochemical reduction of native Ru oxide. Oxide reduction in a tetramethylammonium hydroxide solution was critical for the formation of continuous Ag film, and a large overpotential was important for high-density nucleation. From a kinetics viewpoint, the thermal stability of the Ag film was improved by the application of a more negative potential, which suggested that better nucleation density at the initial stage of growth induced better substrate adhesion. Suppression of growth by addition of an organic additive generated a larger and more uniformly distributed initial population of Ag particles, and as a result a smooth film was obtained.