Reliability of CVD Cu buried interconnections

CVD Cu, which is both highly conductive and reliable, has been investigated as an interconnection material. Cu/sup 1+/ (hfac)(tmvs) is the precursor used in this work. Excellent conformality, which is required for reliable high aspect ratio buried interconnection, has been observed and quantified by simulations. Cu diffusion through TiW as thin as 25 nm has been investigated using large area diodes. Drift of Cu through various dielectrics has been observed, demonstrating the necessity of diffusion barriers. Electromigration studies indicate that Cu interconnections are more reliable than Al alloys.<>