A chemical vapor deposition method for producing a porous organosilica glass film comprising: introducing into a vacuum chamber gaseous reagents including at least one precursor selected from the group consisting of an organosilane and an organosiloxane, and a porogen that is distinct from the precursor; applying energy to the gaseous reagents in the vacuum chamber to induce reaction of the gaseous reagents to deposit a preliminary film on the substrate, wherein the preliminary film contains the porogen; and removing from the preliminary film substantially all of the porogen to provide the porous film with pores and a dielectric constant less than 2.6.