Novel Advanced Low-k Dielectric for 2 nm and Beyond Cu and Post Cu Dual Damascene BEOL Interconnect Technologies

A novel class of mechanically and electrically robust advanced low-k (ALK) dielectrics has been developed. These have far lower plasma-induced damage (PID), excellent builtin Cu oxidation and diffusion barrier performance, and fundamentally more reliable TDDB. One ALK recipe has been fully evaluated as the next generation low-k interlevel dielectric (ILD) for 2 nm and beyond Cu and post Cu dual damascene BEOL¹. The dense ALK (k=3.2) and lightly porous ALK (k=2.8-3.0) films have high modulus (E ∼ 15-33 GPa), from ∼ 1 / 2 to ∼ 1 / 10 the PID of typical dense SiCOH (k ∼ 2.7 3.2) or pSiCOH (k ∼ 2.4-2.55). The ALK Cu and O diffusion barrier properties enable further scaling of metal barriers, to increase Cu line volumes, reducing R, RC while actually improving TDDB and EM. This is confirmed for 2 nm node Cu dual damascene¹ and future subtractive Ru/airgap scheme⁹