Kinetic Self-Assembly of Metals on Co-polymer Templates

TL;DR

This paper investigates the fundamental processes of nanoscale self-assembly of metals on co-polymer templates, emphasizing the roles of energetics and kinetics, and demonstrates how kinetic mechanisms explain observed wire-like morphologies and correlations.

Contribution

It provides a kinetic-based explanation for the formation and correlations of metallic nanostructures on patterned co-polymer templates, supported by experimental and simulation comparisons.

Findings

Morphologies depend on energetics and kinetics.

Kinetic mechanisms explain wire correlations.

Simulations match experimental data.

Abstract

In this work we seek to understand some of the fundamental processes that govern self-assembly at the nanoscale in the context of the formation of metallic structures on patterned co-polymer templates. To this end we focus on the experiments conducted by Lopes {\it et al} (Nature, 2001), where morphologies resulting from the evaporation-deposition of different metals on PS-b-PMMA phase separated templates were studied. We show that the different morphologies obtained can be understood in terms of the relative importance of the energetics and kinetics. We then focus on a particular morphology: micron long wire-like states obtained by the evaporation-deposition of silver on the template. We show the existence of ``non-trivial'' correlations between adjacent wires that can be understood based on a purely kinetic mechanism. We also compare these correlations quantitatively to those obtained from simulations done with the relevant experimental parameters and find them in good agreement.