Titre :
Let's Do the Twist: From Epitaxial Block Copolymer Nanopatterns to Graphene Bilayers
Endroit: Pavillon J. Amand Bombardier, Salle 1035
Hôte : Prof. William Skene
Résumé : À venir
Nanopatterned surfaces are of central importance to a variety of areas and applications, such as computer chip architectures, tissue interfacing, biosensors, light management and plasmonics, among others. Typically, the various approaches to nanopatterning of surfaces, including silicon, are broken into two major classes: top-down methods such as photolithography, e-beam lithography and scanning force microscopy variants, and bottom-up synthetic techniques, including self-assembly. Since lithography is the single most expensive step in computer chip manufacturing, the use of self-assembled block copolymers (BCPs) templates on surfaces is being seriously considered by the semiconductor industry to pattern sub-20 nm features on a semiconductor surface; the Industry Technology Roadmap for Semiconductors (ITRS) terms this approach ‘directed self-assembly’, or DSA.1 Here, we will describe the remarkable versatility of using BCPs, polymers that contain sufficient chemical information to form highly ordered templates over large areas. Recently, experimental observation of static distortion waves (SDWs), local chiral twisting of lattices, has become a topic of extreme interest in the area of graphene-based patterns and structures2 - perfect timing, since we have discovered unable SDWs in block copolymer-based self-assembled structures that are at least an order of magnitude larger in scale, and could thus serve as an easily studied model for these graphene motifs.3
References
- The International Technology Roadmap for Semiconductors: itrs2.net
- Cao, Y. et al Correlated insulator behavior at half-filling in magic-angle graphene superlattices, Nature 2018, 556, 80-84.
- Jin, C. et al Preferential Alignment of Incommensurate Block Copolymer Dot Arrays Forming Moiré Superstructures. ACS Nano 2017, 11, 3237-3246.
