A team of engineers from the University of Illinois at Urbana-Champaign, the University of Chicago, and Hanyang University in Korea has developed a new approach to fabricating nanostructures for the semiconductor and magnetic storage industries. This approach combines advanced ink-jet printing technology with self-assembling block copolymers, a type of material that can spontaneously form ultrafine structures.
The researchers were able to increase the resolution of their intricate structure fabrication from approximately 200 nanometers to approximately 15 nanometers. The ability to fabricate nanostructures out of polymers, DNA, proteins, and other “soft” materials could enable new classes of electronics, diagnostic devices, and chemical sensors. The problem is that many of these materials are fundamentally incompatible with the sorts of lithographic techniques that are traditionally used in the integrated circuit industry.
Recently developed ultrahigh resolution ink jet printing techniques have demonstrated resolution down to 100 to 200 nanometers, but there are significant challenges in achieving true nanoscale dimension. But they say that their work demonstrates that processes of polymer self-assembly can work around this limitation.
Combining jet printing with self-assembling block copolymers enabled the engineers to attain the much higher resolution. They first created either a topographical or chemical pattern using traditional processes and then placed a block copolymer atop this pattern. The advanced form of inkjet printing the engineers used to deposit the block copolymers is called electrohydrodynamic printing, or e-jet printing, which operates much like an office inkjet printer. The block copolymer self-organizes, directed by the underlying template to form patterns that are at much higher resolution than the template itself.