Modified multilayered metal line structure for use with tungsten-filled vias in integrated circuit structures

摘要

A composite metal line structure for an integrated circuit structure on a semiconductor substrate is disclosed which comprises: a low resistance metal core layer; a first thin protective layer of electrically conductive material on the upper surface of the metal core layer capable of protecting the metal core layer from reaction with tungsten; a layer of tungsten formed over the first protective layer to function as an etch stop layer for vias subsequently formed in an overlying dielectric layer; and a second thin protective layer of electrically conductive material over the tungsten layer and capable of functioning as an antireflective coating (ARC). When a dielectric layer is formed over the composite metal line structure, tungsten-filled vias can be formed in the dielectric layer which will extend down through the second thin protective layer to provide direct electrical contact between the tungsten-filled via and the tungsten layer of the composite metal line structure, thereby providing a low resistance contact between the tungsten-filled via and the composite metal line structure.