Cylinder Alignment in Annular Structures of Microphase-Separated Polystyrene-b-Poly(methyl methacrylate)

We present a novel and simple method for generating micron-scale annular structures formed from polystyrene- b -poly(methyl methacrylate) (PS- b -PMMA) diblock copolymer on a silicon oxide substrate. This method is based on prewetting of the underlying substrate with a minor polar solvent before spin-casting of the diblock solution. When using this procedure, we also see, using atomic force microscopy, a unique alignment effect which occurs in the cylinder-forming microdomains of PS- b -PMMA annuli without the aid of an external alignment field. These aligned microdomains, with controlled nanometer-scale spacing and coherence on the order of microns, facilitate the ongoing exploration of self-organizing nanofabricated surfaces.