| 摘要 |
PROBLEM TO BE SOLVED: To improve a copper wiring in resistance to electromigration by a method wherein barrier metal is formed into a two-layered laminated barrier metal film used for an embedded metal wiring, a first barrier metal layer comes into contact with wiring metal and is satisfactory in adhesion to it, and a second barrier metal layer comes into contact with an inter-wiring insulating film and is made to serve as a diffusion preventing layer. SOLUTION: A first interlayer insulating film 2 is formed on a silicon substrate 1, an inter-wiring insulating film 3 is formed on the interlayer insulating film 2, a wiring groove is provided to the insulating film 3, a first and a second barrier metal layer, 6 and 7 are formed on the inner wall and base of the wiring groove, and copper is filled up in the groove for the formation of a copper wiring 8. The first barrier metal layer 6 serves as a barrier film to prevent copper from diffusing into the inter- wiring insulating film 3, and the second barrier metal 7 is satisfactory in adhesion to the copper wiring 8. Furthermore, a second interlayer insulating film 9 is formed to constitute an upper wiring structure. The second interlayer insulating film 9 prevents copper from diffusing into the upper wiring structure and functions as a stopper in dry etching carried out for the formation of a wiring groove when the upper wiring structure is formed. The above processes are repeatedly carried out for the formation of a multilayer interconnection structure.
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