METAL INTERCONNECT STRUCTURE AND METHOD FOR FORMING METAL INTERCONNECT STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a conformal adhesion promoter liner for metal interconnection.SOLUTION: A dielectric layer is patterned to have at least one line trough and/or at least one via cavity. A metal nitride liner is formed on a surface of the patterned dielectric layer. A metal liner is formed on a surface of the metal nitride liner. A conformal copper nitride layer is formed directly on the metal liner by atomic layer deposition (ALD) or chemical vapor deposition (CVD). A Cu seed layer is formed directly on the conformal copper nitride layer. The at least one line trough and/or the at least one via cavity is filled with an electroplated material. The direct contact between the conformal copper nitride layer and the Cu seed layer provides enhanced adhesion strength. The conformal copper nitride layer may be annealed to convert an exposed outer portion into a continuous Cu layer, which may be employed to reduce the thickness of the Cu seed layer.