MTL Annual Research Report 2011

Self-organized macromolecular materials can provide an alternative pathway to conventional lithography for the fabrication of devices on the nanometer scale. In particular, the self-assembly of the microdomains of diblock copolymers within lithographically-defined templates to create patterns with long range order has attracted considerable attention, with the advantages of cost-effectiveness, large-area coverage, and compatibility with preestablished top-down patterning technologies. Previously, we showed that spherical morphology poly(styrene-b-dimethylsiloxane) (PS-PDMS) block copolymers, which have a large interaction parameter and a high etch-contrast between two blocks, can be templated using an array of nanoscale topographical elements that act as surrogates for the minority domains of the block copolymer ^[1] . Recently, we showed that complex nanoscale patterns can be generated by combining the self-assembly of block-copolymer thin films with minimal top-down templating. A sparse array of nanoscale HSQ posts was used to accurately dictate the assembly of a cylindrical PS-PDMS diblock copolymer into a wide assortment of complex, unsymmetrical features, as shown in Figure 1 ^[2] . To extend the feature sizes to the sub-10-nm range, we demonstrated the formation of highly ordered grating patterns with a line width of 8 nm and period of 17 nm from a self-assembled PS-PDMS diblock copolymer and fabricated sub-10-nm-wide tungsten nanowires from the self-assembled patterns using a reactive ion etching process, as shown in Figure 2.