Electrodeposited Cu Film Morphology on Thin PVD Cu Seed Layers

Abstract

The electrodeposited Cu film morphology on thin physical vapor deposited (PVD) Cu seed for various conditions is discussed. Thinner PVD Cu seed on Ta yields isolated electrodeposited Cu particles, while smooth plated films are obtained for thicker seed. Changes in virgin makeup solution (VMS) concentrations have a limited impact on the morphology of Cu electrodeposited on thin Cu seed. Increased seed to plate queue time appears to lead to coarser, more isolated deposited Cu particles. A chemical vapor deposited (CVD) Co liner appears to improve the effective thickness of PVD Cu seed and hence the electrodeposited Cu film morphology for conditions considered in this study.