Fabrication of a Molecular Self-Assembled Monolayer Diode Using Nanoimprint Lithography

We report a simple parallel process for the fabrication of nanoscale electrical contacts to probe the conductance characteristics of a molecular self-assembled monolayer (SAM) using nanoimprint lithography (NIL), a patterning technology capable of sub-10 nm resolution. We fabricated multiple samples, each with 40 gold contacts to a commonly investigated SAM, octadecanethiol (C-18). The contacts were fabricated by growing a SAM on gold nanowire and then patterning a second gold wire over the SAM. The electrical conductivity characteristics of the molecule can be reproduced between samples, suggesting a reliable fabrication process. Our procedure can be employed to study the conductance of any candidate thiol-terminated SAM of interest. Such flexibility permits extensive study of molecular devices and optimization of the processing required to merge silicon with molecular self-assembly.