Highly-reliable molecular-pore-stack (MPS)-SiOCH/Cu interconnects with CoWB metal-cap films

Abstract

Highly-reliable molecular-pore-stack (MPS)-SiOCH (k=2.5)/Cu interconnects with CoWB metal-cap have been developed. The MPS-SiOCH film is suitable for CoWB metal-cap by self-aligned electroless plating because of its unique pore-structure such as small-closed pores in carbon-rich SiOCH matrix. The MPS-SiOCH film suppresses the Co diffusion into the film and metal residue on the surface during the metal-cap process, achieving high TDDB reliability as well as improving reliabilities of EM and SiV remarkably. A combination of the MPS-SiOCH/Cu line and the CoWB metal-cap is a strong candidate for highly reliable LSIs.