Structure for protecting copper interconnects in low dielectric constant materials from oxidation

A diffusion barrier of dense material for protecting a copper structure from oxidation in the presence of oxygen or water in an integrated circuit but subject to defects such as pinholes is repaired in-situ by oxidation of a material capable of forming a protective oxide in a self-limiting manner which is placed in contact with the dense material, preferably as a film. This provision of protection for copper structures allows the high conductivity of copper to be exploited in combination with low dielectric constant (low K) materials, that are now recognized to support diffusion of oxygen and water, to enhance signal propagation speed.