Molecular Templating of Nanoporous Ultralow Dielectric Constant (≈1.5) Organosilicates by Tailoring the Microphase Separation of Triblock Copolymers

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 to fabricate nanoporous organosilicates. The triblock copolymers microphase-separate into nanometer domains as the MSQ matrix becomes increasingly hydrophobic during a curing step. Extremely small pores (2−5 nm) are generated after thermally removing the template material. These materials attain ultralow dielectric constants (k ≈ 1.5) with electrical and mechanical integrity.