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 built-in 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 BEOL. 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 (k2.7-3.2) or pSiCOH (k2.4-2.55). The ALK Cu and $O_2$ 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 scheme.