Study of Cu-CMP process performance for interconnects using new Cu slurries

摘要

In the present study, two new experimental copper (Cu) slurries were evaluated using Cu/SiO_2 pattern wafers and their performances were compared with commercial slurry. With stringent polishing non-uniformity (NU%) target, various experiments were conducted with different oxidizer content and flow rate. It is observed that removal rate decreases with decrease of oxidizer content for both slurries. Post Chemical Mechanical Planarization (CMP) dishing is lower than the commercial slurry due to the adsorbed organic film that passivates copper during its polishing in the experimental slurries. Cu dishing of less than 30 nm were obtained without its residual copper remaining on the wafers.