Interlayer insulation film

Patent Granted This invention aims at providing an interlayer insulation film of a semiconductor device that has a low dielectric constant and is stable without generation of a gas such as CFx and SiF4, and providing a wiring structure having the interlayer insulation film. According to the wiring structure of this invention, in the interlayer insulation film having an insulation film formed on an underlying layer, the interlayer insulation film has an effective dielectric constant not higher than 3.