WIRING STRUCTURE AND METHOD FOR FORMING SAME

摘要

Disclosed is a wiring structure wherein increase in the leakage current and increase in the wiring resistance due to oxidation can be avoided and electromigration does not easily occur. Consequently, the wiring structure has even higher reliability in comparison to conventional wiring structures. Also disclosed is a method for forming the wiring structure. After forming a copper wiring line above a substrate, the surface of the copper wiring line is activated by carrying out acid cleaning. Then, the substrate is immersed in an aqueous benzotriazole (BTA) solution, thereby forming a protective film that covers the surface of the copper wiring line. At this time, Cu-N-R bonds (wherein R represents an organic group) are formed at grain boundary portions in the surface of the copper wiring line. After that, the protective film is removed by carrying out alkali cleaning. After the removal of the protective film, the Cu-N-R bonds remain at the grain boundary portions in the surface of the copper wiring line. Then, after activating the surface of the copper wiring line, a barrier layer is formed by electroless plating NiP or CoWP on the surface of the copper wiring line.