Propagatable Hierarchical Architectures from Dispersive Fragments to Periodic Nanosheets within Phase-Separated Nanostructures by Controlling Guest-Host Interaction

Nanomaterials with a hierarchical organization of multiple scales are critical for reducing line width in semiconductor manufacturing. We design nanohybrid materials with a hierarchical or homogeneous phase of polyhedral oligomeric silsesquioxane (POSS) nanoparticles by controlling guest-host and guest-guest interactions. The guest POSS nanoparticle with the single-acid-terminated (MA-POSS) or octa-acid-terminated (OMA-POSS) functionality is introduced into a host polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) block copolymer. As the MA-POSS concentration is low, the stronger self-association (guest-guest interaction) between the MA-POSS nanoparticles and the weaker hydrogen bonding force (guest-host interaction) between the P2VP and the MA-POSS result in the formation of dispersive fragments in the chain end of the P2VP block. With increasing MA-POSS concentration, the fragment can grow into a single nanosheet parallel to the lamellar P2VP microdomain and then continuously develop into the periodic tri-nanosheet and quadro-nanosheet. In contrast, introducing the octa-acid-terminated OMA-POSS with enhanced guest-host interaction leads to the homogeneous dispersion of the OMA-POSS cluster in the P2VP microdomain, independent of the OMA-POSS concentration. Moreover, owing to distinct etch contrast among the inorganic POSS and the organic block copolymer, the well-defined line pattern of nanosheets of a few nanometers can be observed. Consequently, the hierarchical structures with the propagatable nanosheet of similar to 4 nm or homogeneous dispersion of the POSS nanoparticles within the microphase-separated P2VP microdomain can be well controlled, providing a means of designing nanohybrid materials with distinct distributions of the functional nanoparticles.