Co, a candidate material for barrier and capping layers in 10 nm and smaller Cu interconnects, is prone to corrosion and galvanic corrosion during chemical mechanical planarization (CMP) and wet cleaning in aqueous environments posing a serious challenge to its use since the Co liner in the advanced nodes is desired to be only ∼2 to 3 nm thick. We show that E corr between Cu and Co (2 nm) films can be reduced to <10 mV, with Cu being more noble, in an aqueous solution of 6.6 mM (0.05 wt%) Glycine + 15 mM 1,2,4 Triazole, while maintaining an excellent surface finish making it an excellent cleaning solution for Cu/Co (2 nm) structures. We also show that such thin Co films behave electrochemically very differently from thicker (physical vapor deposited 200 nm and even 20 nm) films, perhaps due to differences in deposition methods, differences in surface interactions as determined by XPS and in grain sizes as revealed by SEM imaging, and that (post-CMP) cleaning solutions available for the thicker films do not work for them.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.