Copper Plating on Resistive Substrates, Diffusion Barrier and Alternative Seed Layers

Abstract

We have studied electrochemical deposition of copper on ruthenium-tantalum (Ru-Ta) alloy, tantalum (Ta), and cobalt (Co) substrates using cyclic voltammetry and galvanostatic methods. We show that a single-step direct-plating from acidic Cu bath approach is favorable on thin Ru-Ta films, while it presents a significant challenge for plating on resistive Ta and Co substrates.