Block copolymer lithography approach to
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.