A process for enhancing the adhesion of directly plateable materials to an underlying dielectric is demonstrated, so as to withstand damascene processing. Using diffusion barriers onto which copper can be deposited facilitates conventional electrolytic processing. An ultra-thin adhesion layer is applied to a degassed, pre-cleaned substrate. The degassed and pre-cleaned substrate is exposed to a precursor gas containing the adhesion layer, optionally deposited by a plasma-assisted CVD process, resulting in the deposition of an adhesion layer inside the exposed feature. The treated wafer is then coated with a diffusion barrier material, such as ruthenium, so that the adhesion layer reacts with incoming diffusion barrier atoms. The adhesion layer may be selectively bias-sputter etched prior to the deposition of the diffusion barrier layer. A copper layer is then deposited on the diffusion barrier layer.