| Abstract
| - Triblock polymers, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO), are used as molecular templates in poly(methyl silsesquioxane) (MSQ) matrixes tofabricate nanoporous organosilicates for low dielectric constant applications. The resultsshow that aggregation of block copolymers in the MSQ matrix can be prevented with thefast solvent evaporation which accompanies spin casting. Solid-state NMR shows that thetriblock copolymer microphase-separates from the MSQ during a curing step, resulting inpolymer domain size in the range of 3−15 nm, depending upon the polymer compositionand loading percentage. When the films are heated to 500 °C, extremely small pores (2−6nm) are generated, which are studied by small angle neutron scattering and positroniumannihilation lifetime spectroscopy. These materials attain ultralow dielectric constants (k≈ 1.5) with good electrical and mechanical properties.
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