Dielectric reliability of 70 nm pitch air-gap interconnect structures

摘要

Scaling air-gap interconnects to 70 nm pitch is demonstrated for the first time by combining air-gap technology (SiO_2 etch-back and non-conformal CVD) and the double patterning approach. A capacitance reduction of 45% was measured on the air-gaps compared to the SiO_2 reference. The reliability performance of the air-gaps was then evaluated and it was found that the structures exceeded 10 years lifetime at 2 MV/cm, almost matching the performance of SiO_2 interconnects. Air-gaps could therefore make a promising low-RC solution for future technology nodes.