Abstract: A semiconductor device and method of manufacture thereof having a less free fluorine (F) fluorine containing Silica Glass (FSG) dielectric film formed thereon. The FSG dielectric film includes about 25% or less free F, has a porosity of about 5% or less and has a dielectric constant of about 3.8 or less. A first barrier layer may be disposed between a workpiece and the FSG dielectric film, and a second barrier layer may be disposed between the FSG dielectric film and at least one conductive line formed in the FSG dielectric film. The FSG dielectric film is formed by introducing SiF4:SiH4 at a reaction condition ratio of about 2.5 or less at a pressure of about 3 Torr or less and at an RF of about 500 watts to 5000 watts.