US Patent 7851917 Wiring structure and method of manufacturing the same

A wiring structure includes a first wiring, a first interlayer dielectric film having a first opening, a second wiring formed with a first recess portion on a region corresponding to the first opening, a second interlayer dielectric film having a second opening and a third wiring so formed as to cover the second interlayer dielectric film, wherein an inner side surface of the second opening is arranged on a region corresponding to the first recess portion and formed such that an opening width of a portion in the vicinity of an upper end increases from a lower portion toward an upper portion.