Co-existing Nanostructures of Lamellae and Cylinders by A1BA2C Tetrablock Terpolymer

Nanopatterns with multiple shapes, such as lines and dots, in a single substrate are needed for the next-generation nanolithography. Here, we observed, via small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), co-existing morphologies of lamellae and cylinders by careful control of volume fraction of each block in polystyrene-b-polyisoprene-b-polystyrene-b-poly(2-vinylpyridine) tetrablock terpolymer (S₁IS₂V). The PI cylinders are located inside PS lamellae, but close to the interface of PS/P2VP lamellae. The experimentally observed morphology is in good agreement with the predicted phase by self-consistent filed theory (SCFT). Finally, we obtained vertically oriented co-existing nanostructures on a substrate by using solvent vapor annealing (SVA) and confirmed the orientation of co-existing nanopattern by grazing-incidence small angle X-ray scattering (GI-SAXS) and atomic force microscopy (AFM).