Nanotech methods for making very small electronic devices may benefit from a new ability to make block copolymers self-assemble into square arrays. From nanotechweb.org, written by Belle Dumé (requires free registration), “Self-assembly goes square-shaped“:
Researchers in the US are the first to use self-assembly to make highly-ordered square arrays from block copolymers. Each square measures about 20 nm and the team believes that the technique could someday be used to make extremely small electronic devices. Until now, block-copolymer self-assembly methods could only produce hexagonal-shaped arrays, which are not compatible with the industrial processes used to make integrated circuits.
Self-assembled square arrays are a major goal for researchers because the semiconductor industry’s circuit design, software and fabrication processes are all based on a rectilinear coordinate system. Although hexagonal patterns can now routinely be produced using conventional self-assembly techniques, adopting these shapes would mean rethinking semiconductor industry protocols, which would be very expensive and time-consuming. To this end, the Semiconductor Industry Association has set up a challenge to scientists working in the field of “block copolymer” lithography to develop square arrays of etchable block copolymer domain patterns.
…The new technique developed by a multidisciplinary team at the University of California, Santa Barbara … involves using an mixture or “alloy” of two different block copolymers that have an attractive hydrogen-bonding interaction with each other.
The research was published in Science [abstract].