Center for Functional Nanomaterials Seminar

The directed self-assembly (DSA) of block copolymers (BCPs) has attracted significant interest as an extension to lithography by enhancing resolution and improving dimensional uniformity. Typically, DSA offers a limited set of dense and highly periodic patterns; on the other hand, integrated circuit fabrication require more complex patterns customized according to design. This talk will discuss recent advances toward customizable nanoscale fabrication based on the DSA of lamellae-forming polystyrene-block-poly (methyl methacrylate) thin films using underlying, partially inorganic chemical guiding patterns. As the foundation of these advances, a new route to create customized BCP patterns is introduced by encoding chemical patterns with inorganic guiding lines and non-guiding "masking" features. Subsequent DSA and pattern transfer results in line-space gratings with gaps between lines and trim across lines dictated by the placement of guiding lines and masking features, respectively. Thermodynamic analysis reveals the rules governing chemical pattern and process design in order to achieve defect-free BCP assembly with pattern customization over large areas. Furthermore, designing these "hybrid" organic-inorganic chemical patterns in an opposite pattern tone with guiding trenches in place of guiding lines affords greater design flexibility and illustrates a path to integrate BCP DSA into high-volume integrated circuit manufacturing. These self-aligned, bidirectional customization schemes create new opportunities for high-resolution, circuit-relevant patterning using DSA.