Replication of Vertical Features Smaller than 2 nm by Soft Lithography

This communication demonstrates a simple, soft lithographic approach to the replication and metrology of nanoscale vertical displacements. We patterned test structures with regular patterns that minimize artifacts in measurements by atomic force microscopy. A composite stamp of poly(dimethylsiloxane) (PDMS) molded against the original test structure served as a template to generate polyurethane replicas. We replicated vertical displacements down to ∼1.5 nm. This replication demonstrates the capability of soft lithography to reproduce features with dimensions similar to those of large molecules.