Dielectric reliability of 70nm pitch air-gap interconnect structures

Abstract: Scaling air-gap interconnects to 70nm pitch is demonstrated for the first time by combining air-gap technology (SiO2 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 SiO2 reference. The reliability performance of the air-gaps was then evaluated and it was found that the structures exceeded 10years lifetime at 2MV/cm, almost matching the performance of SiO2 interconnects. Air-gaps could therefore make a promising low-RC solution for future technology nodes. [Copyright &y& Elsevier]