Templating nanoporosity in thin-film dielectric insulators

In this article, two routes to the preparation of nanoporous thin films are described. The first approach involves the preparation of block copolymers capable of self-assembly in which the continuous phase is a thermally stable polymer and the dispersed phase is thermally unstable. Upon a high-temperature treatment, the unstable component undergoes thermolysis, leaving behind pores with a size and shape dictated by the initial morphology. The second approach uses well-defined branched and highly functional macromolecules that function as molecular templates during the vitrification of the SSQ. Once the organic component nanoscopically organizes the inorganic component, the temperature is increased to decompose the organic component and leave behind the nanoporous structure. In both approaches, thin films having closed-cell porosity and dielectric constants ≤2.2 were demonstrated.