A process for treating silica dielectric film on a substrate, which includes reacting a suitable hydrophilic silica film with an effective amount of a multifunctional surface modification agent. The film is present on a substrate and optionally has a pore structure with hydrophilic pore surfaces, and the reaction is conducted for a period of time sufficient for said surface modification agent to penetrate said pore structure and produce a treated silica film having a dielectric constant of about 3 or less, wherein the surface modification agent is hydrophobic and suitable for silylating or capping silanol moieties on such hydrophilic surfaces. Dielectric films and integrated circuits including such films are also disclosed.