The Effect of an Antigalvanic Reduction of Silver on Gold for the Stability of a Self-Assembled Alkanethiol Monolayer and Chemical Lift-Off Lithography

Abstract

The effects of silver antigalvanic reduction (Ag AGR) on the structure of alkanethiol self-assembled monolayers (SAMs) on gold with regard to the ordered structure and surface coverage were studied using electrochemical methods. In this paper, we report the structure changes as well as the chemical lift-off lithography (CLL) performance of SAMs dependent on chain lengths, namely, 1-butanethiol, 6-mercapto-1-hexanol, and 11-mercapto-1-undecanol. Cyclic voltammetry of the redox probe and linear sweep voltammetry of the reductive desorption demonstrated that the structure of SAMs with Ag AGR pretreatment are more ordered, resulting from higher surface coverage and stronger molecular interaction. Meanwhile, the influence of Ag AGR on the CLL efficiency behaved differently depending on the SAM chain lengths in both electrochemistry and AFM imaging. In general, the formation of alkanethiol SAMs on Ag AGR/Au has enabled a facile method, which possesses a great potential on the quality control of the SAMs system.