| abstract |
[PROBLEMS] To reduce contact resistance between copper layers and reduce wiring delay in a multilayer wiring composed of copper. In a multilayer wiring structure according to the present invention, a first layer wiring (copper) and a second layer wiring (copper) are electrically connected via a via plug (copper), and the via plug is connected to the wiring. The connection is made of the same kind of metal, and the contact resistance can be made lower than before. Further, in the method for manufacturing a multilayer wiring according to the present invention, after the barrier metal 9 is left on the side surface of the via hole 8 and the surface of the first layer wiring (copper) 4 is exposed, Oxygen plasma treatment, dilute hydrofluoric acid treatment, hexafluoroacetylacetone Gas treatment is sequentially performed to remove oxygen at the connection interface, thereby realizing a reduction in contact resistance. |