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 BEOL<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>. The dense ALK (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{k}=3.2$</tex>) and lightly porous ALK (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{k}=2.8-3.0$</tex>) films have high modulus (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{E} \sim 15-33 \text{GPa}$</tex>), from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 1 / 2$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 1 / 10$</tex> the PID of typical dense SiCOH (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{k} \sim 2.7$</tex> 3.2) or pSiCOH (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{k} \sim 2.4-2.55$</tex>). The ALK Cu and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{O}_{2}$</tex> diffusion barrier properties enable further scaling of metal barriers, to increase Cu line volumes, reducing <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{R}, \text{RC}$</tex> while actually improving TDDB and EM. This is confirmed for 2 nm node Cu dual damascene<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> and future subtractive Ru/airgap scheme<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup>.