An article may include a structure including a patterned metal on a surface of a substrate, the patterned metal including metal features separated by gaps of an average dimension of less than about 1000 nm. A porous low dielectric constant material having a dielectric value of less than about 2.7 substantially occupies all gaps. An interface between the metal features and the porous low dielectric constant material may include less than about 0.1% by volume of voids. A method may include depositing a filling material including a silicon-based resin having a molecular weight of less than about 30,000 Da and a porogen having a molecular weight greater than about 400 Da onto a structure comprising a patterned metal. The deposited filling material may be subjected to a first thermal treatment to substantially fill all gaps, and subjected to a second thermal treatment and a UV radiation treatment.