The Synergetic Effect of Polishing Debris Cleaning in Real-time

Micro-scratch is currently a major problern in CMP process. Scratches can be caused by large agglomerated abrasive particles, pad debris-particle mixture, hardened pad surface. Among such scratch sources, pad debris is suspected as a major contribution to the scratch occurrence. Many efforts were made to reduce micro scratch from pad debris such as high pressure water jet, and uniform distributed diamond conditioner. In present study, to eliminate pad debris as a scratch source, we added vacuum cleaning function into conditioner and conditioner arm. Pad cut rate, removal rate, and scratch count were measured to compare polishing performance between with and without vacuum cleaning. Discharged slurry from conditioner arm also analysed by static light scattering technique to observe large debris size distribution. Keywords: polishing debris, micro scratch, vacuum suction, diamond conditioner