Nanometer-Wide Lines of Self-Assembled Monolayer: A Molecular Dynamics Simulation Study

A molecular dynamics simulation was performed to study the nanometer-wide lines carved out of a self-assembled monolayer (SAM) of octadecanethiol on gold. This simulation is relevant to the nanoscale SAM patterns created by nanolithography. The molecular packing structure in the SAM line was compared with that in a bulk SAM. A stable SAM line must be at least 1.7 nm wide, and two lines can merge if they are less than 3.0 nm apart. This presumably sets the ultimate resolution of SAM patterns. A finite length of the SAM line or the crossing of two lines further destabilizes the SAM line.