Method of manufacturing structure for connecting interconnect lines including metal layer with thickness larger than thickness of metallic compound layer

Abstract

A metal layer ( ), a metallic compound layer ( ) and a metal layer ( ) are stacked in this order when viewed from the side of a first copper interconnect line ( ) and an interlayer insulating film ( ) to constitute a second conductive barrier layer ( ). As the material for the metal layers ( ) and ( ), an element having an atomic weight higher than that of copper such as tungsten (W) or tantalum (Ta) is applicable. A second copper interconnect line ( ) is conductively connected to the first copper interconnect line ( ) at a contact hole ( ) through the second conductive barrier layer ( ). As the ratio of the volume of the second copper interconnect line ( ) at the region for filling a trench ( ) to the volume of the second copper interconnect line ( ) at the region for filling the contact hole ( ) increases, tensile stress to be concentrated at the contact hole ( ) becomes greater. As a result, a void is likely to be generated in the contact hole ( ). In view of this, in order to improve the adhesion especially between the second copper interconnect line ( ) at the region for filling the contact hole ( ) and the second conductive barrier layer ( ), the metal layer ( ) is provided.