Morphology of Metal Films Laser Deposited on Organic Monolayers

Abstract

The topographic characteristics of metal containing films deposited onto self-assembled monolayers (SAMs) are investigated as a probe of the metal-organic interface. The second harmonic (532 nm) of a pulsed Nd:YAG laser is directed onto a rotating and translating metallic (silver) target located in a diffusion-pumped, high vacuum system. The silver is vaporized and deposited onto a dodecanethiol film, a SAM that formed by chemisorption to an annealed gold ball. A quartz crystal microbalance provides a measure of film coverage. A silver-dodecanethiol interface is measured via Atomic Force Microscopy (AFM), which provides a topographic map of the surface. This map yields the morphology of the metal layer with the atomic resolution necessary to understand the nature of the interaction between the metallic film and the organic SAM. Preliminary results show that Ag experiences Volmer-Weber growth on methyl terminated alkanethiol SAM. Future studies will include a hydrophilic terminated SAM.