Our techniques require little in capital investment and most can be carried out in ambient laboratory conditions at low cost. There are, however, important unresolved problems such as distortions in the mask and issues such as runout and registration in multilevel fabrication. Longer term goals include working toward optical data storage systems, flat panel displays, and quantum devices. Soft lithographic techniques are currently not competitive with conventional photolithography for multilayer fabrication where there are critical requirements for pattern regularity. Critical Parameters Soft lithography appears to be a promising route to nanostructures and nanosystems.
Many issues remain to be solved, however, before the techniques can be brought to the market.
Some critical parameters are applicable to all the techniques, while others apply only to specific techniques. Multilevel structures and devices necessitate the ability to accurately place one layer on top of another. Distortion currently limits soft lithographic techniques to the fabrication of single-layer structures and devices. Registration is possible on micron-sized features using a mask aligner. Studies are also underway in our group to quantify the distortion in elastomeric stamps and to limit this distortion by using thick stamps and rigid backings.