Posted: October 21, 2008

Soft method produces hard-to-make nanostructures

(Nanowerk News) Fifty years of Moore's Law-driven reductions in electronic-circuit features sizes are pushing manufacturers toward molecular and atomic dimensions of less than a few nanometers. Unfortunately, it may be impossible or uneconomic for traditional projection photolithographic techniques to create such small features for use in future circuits or newer, different nanotechnology applications.
A conceptually simple set of techniques, called soft lithography, is showing potential for creating some of those needed patterns as well as much more complex three-dimensional nanostructures that are impossible for conventional photolithography to produce. These methods use transparent, rubbery "elastomer" elements with extremely fine relief features created on their surfaces by casting and curing from master templates. These elements are used to produce corresponding relief features in photoresists for conventional photolithographic techniques or to exploit the volumetric intensity patterns that form when the elastomer is illuminated.
At the AVS 55th International Symposium & Exhibition, Dan Shir of the University of Illinois at Urbana-Champaign will describe two recent highlights in his group's soft lithography research: a) High-fidelity molecular-scale replication of the brushed-substrate alignment-layers typically used to make liquid-crystal displays; and b) Exquisite creation of various types of three-dimensional structures 10-100 microns thick, including quasiperiodic and photonic bandgap structures, which could lead to new types of lasers and optical-circuit elements.
Shir's talk, "Techniques for Three Dimensional and Molecular Scale Nanofabrication," will be held at 8 a.m. on Thursday, October 23, 2008, in Room 309 of the Hynes Convention Center.
Source: American Institute of Physics