Template-free alignment of lamellar block copolymers for large area sub-10 nm patterning*

The ever-increasing demand for powerful computing devices necessitates innovative lithographic solutions for increasing the number density of patternable features for use in integrated circuits. Block Copolymer (BCP) self-assembly in thin films offers a promising alternative for patterning sub-10 nm features in the sub-optical lithographic resolution with reduced complexity. Traditionally, BCP alignment for patterning has been achieved using lithographically defined templates. However, the template-free alignment of BCPs for sub-10 nm patterning has not been achieved to date despite the research efforts for the past 2 decades. In this work, we show the template-free alignment of lamellar BCPs for sub-10 nm patterning over large areas. We use thermal shear stress generated by a conformal elastomer during the thermal gradient-based annealing for the self-assembly and the alignment of the vertically oriented lamellar BCPs confined between neutral substrate and topcoat. Furthermore, we use these aligned BCP templates to generate large area aligned gold nanowires having tunable dimensions by a solution-phase infiltration method and BCP template removal.