The demand for low resistance metallization solutions has become an increasingly important issue as interconnect line sizes have approached and in some cases become smaller than the electron mean free path in Cu. Formation of reliable small damascene Cu features with high aspect ratio pose major challenges to void free Cu fill process development. Surfaces and interfaces now begin to play a more dominant role in scaled interconnects, with critical defect sizes becoming much smaller than before. Interfacial engineering between copper and liner/seed, liner/seed to barrier, as well as critical defect control from galvanic corrosion and CuOx nodule formation are also key components of successful metallization development. In this paper, we discuss some critical copper process challenges, focusing on copper barrier/liner, seed, fill, heat treatment, CMP and clean processes development to attain low resistance and reliable metallization.
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.