Dynamic Ordering in High-χ Block Copolymer Lamellae Based on Cross-Sectional Orientational Alignment.

Further development of next-generation block copolymer (BCP) lithography processes is contingent on comprehensive studies of the ordering dynamics of high-χ BCPs that can form sub-10 nm features on thin films. However, quantitative analyses of the degree of ordering on the surface and cross sections of thin films have been difficult to execute. To tackle this challenge, we employ a perpendicular lamella-forming high-χ BCP, poly(polyhedral oligomeric silsesquixone- block -2,2,2-trifluoroethyl methacrylate) (PMAPOSS- b -PTFEMA), and reveal that the high-χ PMAPOSS- b -PTFEMA requires three times the activation energy ( E a ) compared to that of poly(styrene- block -methyl methacrylate) (PS- b -PMMA) for defect annihilation, at E a = 2600 ± 420 kJ mol -1 , and a transition from a fast ordering regime with a growth exponent of Φ = 0.30 at lower orientational order parameters (ψ 2 < 0.36) to a slow ordering regime with Φ < 0.05 at ψ 2 > 0.36, where well-aligned lamellae restrict defect annihilations to enthalpically unfavorable glide mechanisms that require BCP intermixing.