In this work, various vacuum plasma types, generated by either single gaseous sources (N(2) or H(2)) or mixed sources (N(2)-H(2)) are incorporated into an aqueous-solution electrochemical seeding process to pre-treat the surfaces of SiO(2) dielectric layers. Under the optimal plasma atmosphere (monitored by optical emission spectroscopy), the dielectric surfaces can be modified to terminate by hydrophilic bonds, accelerating the adsorption of a crowd of catalytic seeds as small as 3 nm. Such a seeding refinement allows for the growth of a Co-based barrier layer with thickness as thin as 10 nm using electroless plating. Moreover, the capacity of integrating the plasma surface pretreatment with the seeding and electroless-plating process steps to deposit an ultrathin copper-stacked metallization layer in a selective and sequential manner on blanket wafers will be demonstrated by the fabrication of copper-gated and barrier-interposed capacitors. Finally, a tentative work of filling the seeds and the barrier layer into trenches of a patterned wafer was carried out, demonstrating the potential of the reported technique for advanced technology nodes of 60 nm or less. (C) 2010 Elsevier B.V. All rights reserved.