Well-ordered mesoporous silicate films were prepared by infusion and selective condensation of silicon alkoxides within microphase-separated block copolymer templates dilated with supercritical carbon dioxide. Confinement of metal oxide deposition to specific subdomains of the preorganized template yields high-fidelity, three-dimensional replication of the copolymer morphology, enabling the preparation of structures with multiscale order in a process that closely resembles biomineralization. Ordered mesoporous silicate films were synthesized with dielectric constants as low as 1.8 and excellent mechanical properties. The films survive the chemical-mechanical polishing step required for device manufacturing.

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Well-ordered mesoporous silica films were prepared by infusion and selective condensation of Si alkoxides within preorganized block copolymer/homopolymer blend templates using supercritical CO 2 as the delivery medium. The morphologies of the mesoporous silica films reflect significant improvements in the strength of segregation and long-range order of template blends of poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) triblock copolymers with selectively associating homopolymers such as poly(acrylic acid) or poly(4-hydroxystyrene) prior as compared to templates comprised of the neat copolymer. Control over film porosity, pore ordering, and morphology of the films is achieved through simple variations in the homopolymer concentration. The films were characterized using X-ray reflectivity, small-angle X-ray scattering, and transmission electron microscopy.