Surface-induced structure formation of polymer blends on patterned substrates

Phase separation in bulk mixtures commonly leads to an isotropic, disordered morphology of the coexisting phases(1). The presence of a surface can significantly alter the phase-separation process, however(2,3). Here we show that the domains of a phase-separating mixture of polymers in a thin film can be guided into arbitrary structures by a surface with a prepatterned variation of surface energies. Such a pattern can be imposed on a surface by using printing methods for depositing microstructured molecular films(4), thereby allowing for such patterns to be readily transferred to a two-component polymer film. This approach might provide a simple means for fabricating polymer-based microelectronic circuits(5) or polymer resists for lithographic semiconductor processing.