Ultralow-ri materials, low-k dielectric materials, composites, and methods

Abstract

A composition for use in forming low-refractive-index layers includes a siloxane polymer, a porogen, and a curing catalyst that is different from the porogen. The composition can be processed at low temperatures of less than about 125° C. (e.g., about 70-90° C.) to crosslink the polymer. The crosslinked material can be exposed to a developer (e.g., acetone) to remove the porogen, thus forming a low-refractive-index film (e.g., less than about 1.3). A method of forming a nanoporous structure includes applying a composition including a siloxane polymer and a porogen to a substrate. The composition optionally includes a curing catalyst different from the porogen. The siloxane polymer is crosslinked and then contacted with a developer so as to remove the porogen and form pores in the crosslinked composition to yield the nanoporous structure.

Dependencies are inferred from the claim text.