Use of a plating additive to enable continuous metallization of nanoscale electrochemically patterned chemical templates

This paper examines the use of amine-functionalized templates to create nanopatterned metal features. A key aspect of the work is the use of an additive to increase the plating density and enable continuous metallization of nanoscale features. Specifically, MPS (3-mercapto-1-propane sulfonate) was found to increase the plating density of copper on amine-functionalized surfaces by attaching to the surface via the sulfonic acid group, leaving the thiol free to attract palladium ions to the surface. Amine-functionalized nanotemplates were made by selective deposition of PAAm onto surface patterns created by nano-oxidation of OTS-coated silicon substrates. Selective, continuous metallization was observed for MPS-treated nanotemplates. These results demonstrate the successful creation of flexible amine-functionalized nanotemplates, and the enabling influence of MPS for the metallization of nanometer-scale features. In particular, MPS was found to reduce the pattern width for feasible metallization from 500 nm to less than 100 nm. While the PAAm templates were used in this paper to demonstrate selective metallization, they have the potential for broad application in areas such as selective surface attachment of biomolecules to nanometer-scale surface features.