| 摘要 |
A seed layer is formed on a surface of an insulating film and along a recessed section of the insulating film, and after a copper wiring is embedded in the recessed section, a barrier film is formed by heating, and an excessive metal for forming the seed layer is removed from the wiring. At this time, the metal and its oxide remaining in the wiring are suppressed and increase of wiring resistance is suppressed. On a surface of a copper lower layer side conductive path exposed at the bottom of the recessed section, a natural oxide of the copper is reduced or removed. On a substrate from which the natural oxide is reduced or removed, the seed layer is formed. The seed layer is composed of a self-forming barrier metal, which has oxidative tendency higher than that of copper and functions to prevent diffusion of copper by being oxidized, or an alloy of such metal and cupper. The substrate is heated after embedding cupper in the recessed section. Thus, a barrier layer is formed by oxidizing the self-forming barrier metal.At the same time, the excessive self-forming barrier metal is deposited on the surface of the embedded copper. |
