Patent ID: 7799693

Claim:
A method for manufacturing a semiconductor device including a semiconductor substrate, an element formed on said semiconductor substrate, and an insulating film formed on said element, comprising: (a) forming a first conductive layer composed of copper as a main component on said insulating film; (b) forming a first insulating film composed of silicon carbide as a main component on the upper portion of said first conductive layer; (c) forming a second insulating film with a porous structure on said first insulating film; (d) forming a third insulating film different from said second insulating film on said second insulating film; (e) forming a via hole or an interconnect trench in said second insulating film and said third insulating film by dry etching of said third insulating film and said second insulating film in this order; (f) removing a part of said first insulating film by dry etching with said third insulating film used as an etching mask, and a mixed gas consisting of fluorine compound gas and at least one of inert gases and a nitrogen content gas used as an etching gas under the condition where the pressure of said mixed gas in an etching processing chamber is set within a range of 0.1 Pa to 6.0 Pa, such that the surface of said first conductive layer is exposed at the bottom of said via hole or said interconnect trench, said fluorine compound gas including at least one of the gases selected from the group consisting of CF 4 , CHF 3 , CH 2 F 2 , CH 3 F, and NF 3 ; and (g) forming a second conductive material film layer so as to fill said via hole or said interconnect trench.