Method of fabricating dual damascene structure using a hard mask

摘要

A method of fabricating dual damascene structure. A substrate having devices and a defined conductive layer is provided. A dielectric layer and a hard mask material layer are formed respectively over the substrate. An opening is defined within the hard mask material layer. Because of the different selectivity of the hard mask material layer and the dielectric layer, a trench is formed within the dielectric layer by defining the hard material mask layer and a portion of dielectric layer until the conductive layer is exposed. The cross shape of the trench has a wider opening and a narrower bottom. A metal layer is then formed and the trench is filled up with the metal layer. The process of dual damascene structure is accomplished..