Single-Chain-in-Mean Field Simulations and Experimental Studies of Directed Block-Copolymer Assembly on PatternedSubstrates

摘要

Recent studies demonstrate that directing block copolymerassembly on chemically patterned substrates presents an effectivestrategy for creating thin films of regular arrays of supramolecularnanostructures. When the symmetry and the length scales of thepattern match the copolymer bulk morphology, defect free replicationcan be achieved over arbitrarily large length scales.t2 However, forpotential industrial applications, e.g. in nanoelectronics, it is desirablethat the assembled polymer reproduces patterns with non-regular,isolated, device oriented features such as lines, bends, spots e.t.c.Generally, a pronounced mismatch between the symmetry and/or thelength scales of the pattern and those of the bulk morphology will leadto surface reconstruction creating novel supramolecular structures3'4which neither resemble the bulk morphology nor the original twodimensional substrate pattern. Nevertheless, adjusting materialparameters such as blend composition2, molecular architecture andfilm thickness offers opportunities for expanding significantly thecollection of pattern geometries on which perfect assembly can beachieved. This work concentrates on isolated line featuresdemonstrating that their replication is feasible to an extent that allowstheir use as patterning templates in nanotechnological applications.