Patent ID: 7404990

Claim:
A chemical vapor deposition method for producing a porous film represented by the formula Si v O w C x H y F z , where v+w+x+y+z=100 atomic %, v is from 10 to 35 atomic %, w is from 10 to 65 atomic %, x is from 5 to 30 atomic %, y is from 10 to 50 atomic %, and z is from 0 to 15 atomic %, the method comprising: providing a substrate within a vacuum chamber; introducing into the vacuum chamber gaseous reagents comprising at least one structure-former reagent and at least one pore-former reagent that is distinct from the at least one structure-former reagent, wherein the at least one pore-former reagent is a hydrocarbon having from 1 to 13 carbon atoms; applying energy to the gaseous reagents in the vacuum chamber to induce reaction of the gaseous reagents to deposit a multiphasic film on the substrate, wherein the multiphasic film comprises at least one structure-forming phase and at least one pore-forming phase, and the preliminary film is deposited without added oxidants; and exposing the multiphasic film to an ultraviolet light source within a non-oxidizing atmosphere for a time sufficient to substantially remove the at least one pore-forming phase contained therein and provide the porous film comprising a plurality of pores and a dielectric constant of 2.7 or less, wherein the at least one structure-former reagent comprises at least one linear organosilane or organosiloxane selected from the group consisting of: diethoxymethylsilane, tetraethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethylethoxysilane, methyldiethoxysilane, triethoxysilane, trimethylphenoxysilane, phenoxysilane, hexamethyldisiloxane, 1,1,2,2-tetramethyldisiloxane, and octamethyltrisiloxane.