| To broaden the appeal of directed assembly of block copolymers for industrial applications, fundamental studies have been conducted on the free energy minimization of block copolymer films under various boundary conditions. The ordering of block copolymers was found to be dependent on the diffusion of polymer chains and can be modeled as a one parameter Arrhenius Equation with an activation energy. The practical result is that by simply increasing the temperature of annealing, one can achieve assembly in less than one minute, times amenable to rapid manufacturing. In addition, the ability of a surface interaction to direct the assembly could be described by both a phenomenological model equating the change in interfacial energy with the energy requirement for adapting non-bulk like chain configurations, as well as nucleation and growth of polymer domains. The combination of the two mechanisms for assembly allow for films approaching 750 nm in thickness to assemble into large, relatively defect free arrays. The use of topographic features to direct the assembly of block copolymers was also investigated along with the constraints on the quality of the features. For non-preferential wetting conditions, it was found that the roughness of the topographic side walls played only a minor role in defect formation. To expand the role of chemical nano-patterning, a new technique called Molecular Transfer Print and Fill has been demonstrated to produce unique chemical patterns while maintaining pattern fidelity. Furthermore, we demonstrate how the directed assembly of triblock copolymers can result in unique 3D arrangements due to the addition of a third block. |
