Microdomain Orientation of PS-b-PMMA by Controlled Interfacial Interactions

Abstract

The microdomain orientation in thin films of cylinder-and lamella-forming diblock copolymers, polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), was investigated as a function of the film thickness and the composition of random copolymers composed of styrene (S) and methyl methacrylate (MMA), denoted as P(S-r-MMA), that were anchored to the substrate. Using scanning force microscopy (SFM) and grazing incidence small-angle X-ray scattering (GISAXS), the dependence of the microdomain orientation on film thickness around lattice period (or d-spacing, L 0 ), where the microdomain orientations normal to the film surface could be achieved, showed that the optimal condition for the balanced interfacial interactions (the so-called neutrality in random copolymer) was 0.64 of PS mole fraction (X PS ) for the cylindrical microdomain having narrow compositional range of P(S-r-MMA) from 0.52 to 0.72 of X PS , whereas for the lamella microdomain it was observed at X PS ) 0.55 ranging extensively from 0.48 to 0.78.

Improving humidity-controlled solvent annealing processes for block copolymer poly(ethylene oxide)-b-polystyrene

“…1B). This is a significant observation as this level of ordering is sufficient for many applications [55][56][57]. A 1 h annealing increased the average grain size to 1.9 lm  1.9 lm with d = 26 nm.…”

Block Copolymer Nanolithography: Translation of Molecular Level Control to Nanoscale Patterns

“…For the lamellar microdomain, it was observed at X PS ¼ 0.55 with the thickness window ranging from 0.48 to 0.78 of X PS . [27] Although it is not specifically emphasized in the literatures, the optimal molecular weight of the random copolymer is $10 000 g mol À1 , which gives a grafting density of $3 nm 2 chain À1 (thickness of anchored polymer brushes is typically $5-8 nm). [22] Onto this surface, a thin film of PS-b-PMMA BCP is thermally annealed to produce the PMMA cylindrical microdomains oriented normal to the surface.…”

From Self-Assembled Monolayers to Coatings: Advances in the Synthesis and Nanobio Applications of Polymer Brushes

“…These domains are useful for nanolithographic applications [44][45][46][47][48][49][50][51]. In a seminal work of Mansky et al, surface-grafted a hydroxyl terminated poly(styrene-random-methyl methacrylate) (P(S-r-MMA)) brush to modify the interfacial energies between the substrate and the blocks of poly(styrene-block-methyl methacrylate) (P(S-b-MMA)) [2,40,42,[52][53][54][55][56] (Figure 2c,d). …”