Porogens, porogenated precursors and methods for using the same to provide porous organosilica glass films with low dielectric constants

A porous organosilica glass (OSG) film consists of a single phase of a material represented by the formula SivOwCxHyFz, where v+w+x+y+z=100%, 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 %, wherein the film has pores and a dielectric constant less than 2.6. The film is provided by a chemical vapor deposition method in which a preliminary film is deposited from organosilane and/or organosiloxane precursors and pore-forming agents (porogens) wherein the precursor is a compound of the formula R 1 n (OR 2 ) p (O(O)CR 4 ) 3−n−p Si—R 7 —SiR 3 m (O(O)CR 5 ) q (OR 6 ) 3−m−q where R 1 and R 3 are independently H or C1 to C4 linear or branched, saturated, singly or multiply unsaturated, cyclic, partially or fully fluorinated hydrocarbon; R 2 , R 8 and R 7 are independently C1 to C6 linear or branched, saturated, singly or multiply unsaturated, cyclic, aromatic, partially or fully fluorinated hydrocarbon, R 4 and R s are independently H, C1 to C6 linear or branched, saturated, singly or multiply unsaturated, cyclic, aromatic, partially or fully fluorinated hydrocarbon, n is 0 to 3, m is 0 to 3, q is 0 to 3 and p is 0 to 3, provided that n+m>1, n+p 3, and m+q 3, wherein the porogen is selected from the group consisting of norbornadiene, alpha-terpinene, limonene, cyclooctane, and cymene. The porogens are subsequently removed to provide the porous film.