Process optimisation and dual damascene integration of porous CVD SiOC dielectric at 2.4 and 2.2 k-values for 45 nm CMOS technology

Abstract

Dual damascene integration of porous CVD SiOC low-k material was performed for interconnects of the 65 and 45 nm technology nodes. Deposition processes with dielectric constant of 2.4 and 2.2 were developed and characterized. Low-k integration was performed with feature sizes down to 85 nm. Etch and strip processes compatible with this ultra low-k investigated and lead to the successful dual damascene integration, illustrated by physical and electrical results such as low leakage current, via chain and line resistances. The k-value after integration was preserved at its initial value.