Damage-free CMP towards 32nm-node porous low-k (k = 1.6)/Cu integration

To reduce the effective dielectric constant (k/sub eff/) to less than 2.6 for the 45-nm node, direct CMP of a high-modulus porous MSQ (p-MSQ) film (k=2.3, E=10GPa) without a protective cap layer has been successfully applied to 300mm-wafer Cu damascene fabrication by using damage-free CMP process. This process can be extended to the 32nm-node ultra low-k (ULK, k=1.6) CMP with a relatively low-k protective layer by using a newly developed plasma treatment for promoting adhesion, that supports the poor mechanical properties of ULK films (E<1GPa).