Nanolithography Using Hierarchically Assembled Nanowire Masks

A general and scalable method has been developed for patterning nanometer scale lines hierarchically over large areas using nanowires as masks for etching and deposition. Core−shell nanowires with controlled diameter and shell dimensions were aligned with nanometer to micrometer scale pitches using a Langmuir−Blodgett approach and then transferred en mass to planar substrates. Transferred nanowires were used as deposition masks to define metal lines with pitches from the nanometer to micrometer scale over centimeter square areas. Hierarchical parallel nanowire arrays were also prepared and used as masks to define nanometer pitch lines in 10 × 10 μm2 arrays repeated with a 25 μm array pitch over centimeter square areas. This nanolithography method represents a highly scalable and flexible pathway for defining nanometer scale lines on multiple length scales and thus has substantial potential for enabling the fabrication of integrated nanosystems.