US Patent 7998876 Method of producing semiconductor element

A method of producing a semiconductor element includes the steps of forming a wiring portion layer on a substrate; forming an interlayer insulation layer over the substrate and the wiring portion layer, in which a third insulation film, a second insulation film, and a first insulation film are laminated in this order from the substrate; forming a mask pattern on the first insulation film; removing a contact hole forming area of the first insulation film through a wet etching process; removing a contact hole forming area of the second insulation film through an etching process; removing a contact hole forming area of the third insulation film through an etching process; and a contact hole forming step of forming a contact hole in the interlayer insulation layer so that a surface of the wiring portion layer is exposed.