Patterning disorder in monolayer resists for the fabrication of sub-100-nmstructures in silver, gold, silicon, and aluminum

This paper describes the development of a new methodology, "topographically directed etching" or TODE, that relies on patterned regions of disorder in SAMs to generate features specifically at the edges of topographically pat terned metal films. The features that are produced have lateral dimensions of <50 to 200 nm and are at least an order of magnitude smaller than those patterned originally in the material, when the original patterning is at th e scale of mu m. Several variations of this methodology are described, the results of which include the generation of 100-nm trenches in silver, gold, SiO2/Si, and Al2O3/Al, 100-nm lines of:silver, asymmetric structures in al uminum and silver, and 50-nm features in curved silver surfaces. Although t he techniques can be combined with photolithography, the pattern transfer s tep is based on chemical reaction and is therefore not limited by diffracti on or depth of focus. This methodology makes the fabrication of similar to 100-nm structures accessible to chemists/materials scientists without acces s to tools required for electron-beam writing and other procedures of nanof abrication.