Abstract: A semiconductor integrated circuit device has a semiconductor substrate, an interlayer insulating film including SiOF films formed on a main surface of the semiconductor substrate, a wiring groove formed by dry etching of the interlayer insulating film, and a Cu wiring buried in the wiring groove by a Damascene method, wherein a silicon oxynitride film is provided between a silicon nitride film serving as an etching stopper layer for the dry etching and the SiOF film, so that free F generated in the SiOF film is trapped with the silicon oxynitride film.