Electromigration resistance of TiN-layered Ti-doped Al interconnects

The electromigration performance of 2- mu m-wide, 17-mm-long single-layer and TiN-layered Al interconnects was studied. Al-1%Si-0.15%Ti and Al-0.15%Ti-based films were sputter deposited at 200-300 degrees C and 475 degrees C substrate temperatures, respectively. The interconnect lifetime improved dramatically when Al-0.15% Ti alloy was used instead of Al-1%Si-0.15%Ti. A TiN underlayer reduced the Al alloy EM resistance, except when the TiN was exposed to air prior to Al deposition.<
>