Robust Ultrathin (20-25 nm)Trilayer Dielectric Low k Cu Damascene Cap for Sub-30 nm Nanoelectric Devices

Robust ultrathin (20 nm) trilayer low k SiNx/SiNy/SiCNH dielectric Cu caps (k ~4.0-4.2) with post ultraviolet (UV) cure compressive stress were developed and integrated into 22nm CMOS Back End Of Line (BEOL) devices. The new cap reduces device’s capacitance (~ 4 %) and enhances stress stability in Cu-Ultra low k structures.