Block copolymer lithography approach to nanoscale self-assembly

This image created by Seth Darling and Nathan Ramanathan was selected for the September 2009 cover of Materials Today.

Block copolymer lithography represents a promising next-generation alternative to traditional top-down methodologies. The figure shows an optical micrograph of a hybrid organic-organometallic block copolymer thin film cast on a silicon nitride membrane substrate, which reveals thickness-induced coloring effects reminiscent of art glass. This polymer self-assembles into an ordered nanoscale cylindrical morphology, the orientation of which can be controlled with film thickness. Cylinders oriented out of the plane can be used to fabricate dot or post arrays in functional materials by pattern transfer whereas in-plane cylinders can be utilized to fabricate nanowire arrays.