Spectroscopic analysis of a nanostructure roughness of plasma-deposited Au films using organic monolayer

Abstract

The morphology and roughness of nanostructure of Au film are discussed using an atomic-force microscope (AFM) and a laser Raman spectroscopy. The Au films are deposited on mica and Si substrate by means of a dc plasma sputtering technique, and a self-assembled monolayer (SAM) of benzene-thiol is formed on the Au films. The cluster size and roughness on the surface increase with substrate annealing during the deposition on mica substrate, while they decrease on Si substrate. Raman spectra show a surface-enhanced Raman scattering (SERS) occurs at the optimum roughness RA∼0.3 of the substrate.