Patent ID: 7470454

Claim:
A process for preparing a porous film, the process comprising the steps of: forming a composite film onto at least a portion of a substrate by a CVD process, wherein the composite film comprises at least one silicon-based structure-forming material and at least one pore-forming material, and wherein the composite film is substantially free of Si—OH bonds; and exposing the composite film to at least one ultraviolet light source within a non-oxidizing atmosphere for a time sufficient to remove at least a portion of the at least one pore-forming material contained therein and provide the porous film, wherein the silicon-based structure-forming material is formed from at least one gaseous linear organosilane or organosiloxane structure-former reagent selected from the group consisting of: diethoxymethylsilane, tetraethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethylethoxysilane, methyldiethoxysilane, triethoxysilane, trimethylphenoxysilane, phenoxysilane, hexamethyldisiloxane, 1,1,2,2-tetramethyldisiloxane, and octamethyltrisiloxane, wherein the at least one pore-forming material is formed from at least one pore-former reagent wherein the pore-former reagent is a gaseous hydrocarbon having from 1 to 13 carbon atoms, and wherein the pore-former reagent is distinct from the at least one linear organosilane or organosiloxane structure-former reagent.