Long-ranged order cylindrical block copolymer thin films in un-patterned substrates

The microdomain orientation in thin films of cylinder- and lamella- forming polystyrene-block-polymethyl methacrylate (PS-b-PMMA) copolymers on functional poly (styrene-r- methyl methacrylate) P(S-r-MMA) or polystyrene (PS) brushed substrates was studied using field emission scanning electron microscopy (FE-SEM). In order to prepare a well-ordered block copolymer nanotemplate in an equilibrated morphology the substrate material must have reactive functional groups for surface modification as well as extremely low surface roughness. The surface functionality is given by the reactive hydroxyl group at the oxides surfaces. The reactive hydroxyl group could be controlled by modifying in surface cleaning process. The homogeneity of patterned area was increased from about 300 nm to >6 μm after 5 min ultraviolet ozone treatment.