The Extreme Extendibility of Cu and Post-Cu Dual Damascene BEOL Interconnect Technology

After revisiting the previous review [1] of Cu dual damascene BEOL original definitions and continuous, sustaining innovations to the present, we combine several new break-throughs: one novel material; one novel integration enhancement, and one novel unit process. With these, we enable renewed Cu barrier/liner scaling, renewed damascene aspect ratio increase, and continued incremental cap scaling, all with fundamentally increased TDDB and sustained EM reliability. We can therefore target the lowest R and RC vs. wiring pitch to our knowledge. In turn, this can significantly shift projected crossovers with alternate metals and integration schemes. Finally, we add process breakthroughs that enable the first post-Cu metal damascene demonstration using rhodium (Rh), i.e. the lowest resistivity barrier-less metal nanowire option. In Section III, we briefly list facts that contradict the notion that Rh is “too expensive” for semiconductor manufacturing, and will show a detailed cost of ownership sizing at the conference.