We study the orientation of the cylinder phase of the block copolymer (BCP) poly(styrene-block-methylmethacrylate) (PS-b-PMMA) in thin spun-cast films. We hypothesize that the slow solvent evaporation of the flow-coated films leads to films having higher residual stresses than spun-cast films because of a relatively inhibited transport of the solvent out of the film during drying, and annealing measurements on both types of cast films provide supporting evidence that the BCP surface morphology change is associated with residual stresses within the films. Residual stress effects arising during the course of film casting and drying are relevant to other
fabrications involving cast polymer films, such as in organic photovoltaic devices where flow-coating or similar industrial film casting method is normally employed for film formation.
