Patent ID: 7470609

Claim:
A method for manufacturing a semiconductor device, comprising: depositing a first insulating film made of a first low dielectric constant material; depositing a second insulating film having mechanical strength larger than that of the first insulating film thereon; forming a wiring trench in the first and second insulating films; forming a first wiring by filling the wiring trench with a wiring material; forming a conductive film on an upper surface of the first wiring to prevent diffusion of the wiring material; removing the second insulating film; depositing a third insulating film on the first insulating film and the first wiring to prevent diffusion of the wiring material; depositing a fourth insulating film made of the first low dielectric constant material on the third insulating film; planarizing the fourth insulating film to a level of an upper surface of the third insulating film on an upper surface of the first wiring; forming a fifth insulating film made of a second low dielectric constant material on the fourth insulating film and the third insulating film; and forming a plug in the fifth insulating film to interconnect the first wiring and a second wiring to be formed thereon.