Controlling Domain Spacing and Grain Size in Cylindrical Block Copolymer Thin Films by Means of Thermal and Solvent Vapor Annealing

Abstract

Real-time grazing-incidence small-angle X-ray scattering (GISAXS) experiments were used to study the self-assembly of cylinder-forming block copolymers (BCPs) in thin films during thermal annealing and solvent vapor annealing. BCP thin films were annealed in near-neutral solvent vapor for solvent vapor annealing and on a hot plate under an inert gas atmosphere for thermal annealing. The initially ordered films were heated or swollen to induce an order–disorder transition (ODT) and then cooled or the solvent was removed, respectively. The domain spacings of BCPs as determined from in situ GISAXS measurements during solvent removal and cooling were analyzed with respect to the polymer concentration and the reciprocal temperature. Close to the ODT the domain spacing was found to be nearly identical for thermal and solvent vapor annealing. At lower solvent concentrations ϕ and lower temperatures T, the domain spacing was found to increase for both thermal and solvent vapor annealing until structural reorganiz...