title: Improved nanofabrication through guided transient liquefaction.
abstract: A challenge in nanofabrication is to overcome the limitations of various fabrication methods, including defects, line-edge roughness and the minimum size for the feature linewidth. Here we demonstrate a new approach that can remove fabrication defects and improve nanostructures post-fabrication. This method, which we call self-perfection by liquefaction, can significantly reduce the line-edge roughness and, by using a flat plate to guide the process, increase the sidewall slope, flatten the top surface and narrow the width while increasing the height. The technique involves selectively melting nanostructures for a short period of time (hundreds of nanoseconds) while applying a set of boundary conditions to guide the flow of the molten material into the desired geometry before solidification. Using this method we reduced the 3sigma line-edge roughness of 70-nm-wide chromium grating lines from 8.4 nm to less than 1.5 nm, which is well below the 'red-zone limit' of 3 nm discussed in the International Technology Roadmap for Semiconductors. We also reduced the width of a silicon line from 285 nm to 175 nm, while increasing its height from 50 nm to 90 nm. Self-perfection by liquefaction can also be extended to other metals and semiconductors, dielectrics and large-area wafers.
authors.affiliation: Department of Electrical Engineering, NanoStructure Laboratory, Princeton University, Princeton, New Jersey 08544, USA. chou@ee.princeton.edu
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Chou
authors.forename: Qiangfei
authors.initials: Q
authors.lastname: Xia
mesh_terms: D003460:Crystallization / Q000379:methods*; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D044367:Phase Transition; D012825:Silicon / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D012996:Solutions; D012825:Silicon