Semiconductor device and method of manufacturing the same

A method of manufacturing a semiconductor device, comprising the steps of:

• (a) forming a second interlayer insulating film over a substrate;
• (b) forming a second wiring trench in an upper surface of the second interlayer insulating film to form a second wiring by embedding the second wiring in the second wiring trench;
• (c) supplying source gas including porogen to form a first interlayer insulating film over the second interlayer insulating film so as to cover the second wiring;
• (d) eliminating porogen from the first interlayer insulating film by performing UV curing;
• (e) after the (d) step, forming a via hole which passes through the first interlayer insulating film;
• (f) after the (d) step, forming a first wiring trench in an upper surface of the first interlayer insulating film;
• and
• (g) forming a via in the via hole and forming a first wiring by embedding the first wiring in the first wiring trench,
• wherein, the (c) step forms the first interlayer insulating film having a first film and a second film which includes more porogen than the first film, by increasing a porogen flow rate during the formation step of the first interlayer insulating film,
• wherein the (d) step forms a plurality of first vacancies in the first film and forms a plurality of second vacancies having an average diameter larger than an average diameter of the first vacancies in the second film, by eliminating the porogen, and
• wherein the (f) step forms a third film, including a plurality of third vacancies having an average diameter smaller than the average diameter of the second vacancies, on a side wall of the first wiring trench by forming the first wiring trench by plasma etching.