Gold surface with sub-nm roughness realized by evaporation on a molecular adhesion monolayer

Abstract

This letter describes a technique for realizing a gold (Au) surface with roughness at the atomic scale using techniques compatible with integrated device fabrication. The Au layer is electron-beam evaporated on a self-assembled monolayer of (3-Mercaptopropyl) trimethoxysilane on an oxidized silicon substrate and shows a root-mean-square surface roughness of ∼2Å over a 1μm2 area. The physical stability of the Au film toward commonly used chemicals and processes for photolithography and self-assembly, and its suitability for formation of well-ordered organic monolayers indicate that the films are well suited as substrates for future device fabrication in molecular electronics or other devices involving self-assembled monolayers.