Nanoimprint Lithography (NIL) is a technique developed to etch nanoscale designs onto a polymer substrate. This etching technique uses mechanical processes to pattern the surface of a polymer. This mechanical deformation results in precision and consistency that exceed that of conventional lithography techniques that alter the chemical or physical properties of the Polymer. The process is used in the manufacture of a number of devices including non-reflective GaAs solar cells, organic lasers, silicon quantum dots, organic light emitting diode pixels and flash memory. In the case of the latter, NIL has the potential to create flash memory chips that reach data capacities of 1Tb per square inch—the equivalent of a desktop computer hard drive on a surface slightly larger than a thumb nail.
A number of variations of NIL exist or are being refined for commercial use. Thermal or ultraviolet NIL are the most common forms of NIL. Thermal NIL works by coating a substrate material with a layer of polymer (the resist), and imprinting this polymer with a mold. Once imprinted, the polymer is etched away by O2 plasma cutting, leaving the positive relief and exposed substrate channels. UV-NIL only differs in that the resist is applied and cured via UV light. Jet and Flash Imprint Lithography (JFIL), a variation of UV-NIL is the most likely technology moving forward in the semiconductor device and patterned-media storage device industry roadmap due to the technique’s low temperature and low-pressure process.
The potential risks of this technology are dependent on the specific type of NIL technology used, but are analogous to those of the semiconductor industry.