ELECTRONIC STRUCTURE

摘要

A method for fabricating a dual damascene coper interconnect which electrically contacts a damascene tungsten wiring level (190) comprising forming a first layer on a semiconductor substrate, a silicon nitride layer (140) on the first layer, and a silicon dioxide layer (150) on the silicon nitride layer. The first layer includes damascene tungsten interconnect regions separated by electrically insulating material. A continuous space (630) is formed by etching two contact throughs (910) through the silicon dioxide and silicon nitride layers to expose damascene tungsten interconnect regions, and by etching a top portion of the silicon dioxide layer between the two contact throughs. A reduced-height portion of the silicon dioxide layer remains between the two contact troughs. The continuous space is filled with damascene copper. The resulting dual damascene copper interconnect electrically contacts the exposed damascene tungsten interconnect regions.