Patent ID: 7115518

Claim:
A method for fabricating a semiconductor device comprising the steps of: forming a first insulating film made from a silicon nitride film, a silicon nitride oxide film or silicon carbide film on an insulating film made from a silicon oxide film with which a contact plug is formed; forming a second insulating film made from a silicon oxide film on said first insulating film; forming an upper hole in said second insulating film by performing selective etching on said second insulating film in a chamber of a high density plasma etching system by using a first etching gas including a fluorocarbon gas having a cyclic structure as a principal constituent; forming a lower hole continuous to said upper hole in said first insulating film to expose the contact plug and the insulating film with which the contact plug is formed by performing selective etching on said first insulating film in said chamber by using a second etching gas including an oxygen gas as a principle constituent; and forming a storage electrode of a capacitor on a bottom and a wall of a hole consisting of the upper hole and the lower hole, wherein said second etching gas exhibits an etching rate against said insulating film lower than said first insulating film.