Performance and reliability of airgaps for advanced BEOL Interconnects

In this paper we present new modeling and measured data to address detailed performance and reliability considerations of multi-level airgaps. Using finite element modeling, we analyzed the capacitance distributions in the airgaps while restricting openings in the cap layers for increased mechanical and electrical reliability. Despite this restriction, capacitance reductions can be maximized by expanding the gap in the low-k SiCOH dielectric underneath the cap, and by increasing gap depth. Relevant BEOL simulation, performance and reliability data has been obtained and will be presented in this context