Nanolithography using molecular films and processing

This article focuses on the use of molecular films as building blocks for nanolithography. More specifically, it reviews efforts aimed at utilizing organic molecular assemblies in overcoming the limitations of lithography, including self-patterning and directed patterning. It considers the methods of patterning self-assembled organic monolayer films through soft-lithographic methods such as microcontact printing and nanoimprint lithography, through direct ‘write’ or ‘machine’ processes with a nanometer-sized tip and through exposure to electron or photon beams. It also discusses efforts to pattern the organic assemblies via the physicochemical self-assembling interactions, including patterning via phase separation of chemically different molecules and insertion of guest adsorbates into host matrices. Furthermore, it examines the efforts that have been made to couple patterned molecular assemblies with inorganic thin-film growth methods to form spatially constrained, three-dimensional thin films. Finally, it describes a hybrid self-assembly/conventional lithography (i.e. molecular rulers) approach to forming nanostructures.