Pad Surface Variation and its Effect on SiO2 Removal Rate in Ceria-based CMP Slurry

Ceria based slurry have been extensively applied to chemical mechanical planarization (CMP) such as STI (shallow trench isolation) and inter-level dielectric (ILD) process. Taken bulk SiO
2
into account, high removal rate is one of the important factors. The material removal rate depends upon the surface properties of the polishing pad and the conditioning process. Without regeneration of the pad surface during polishing, the removal rate of oxide rapidly increases. By evaluating the regeneration of the pad surface during polishing, the relationship between polishing pad surface feature regeneration and the effect on polish rates is analyzed. In addition, pad is one of the key factors to affect removal rate. Removal rate has a stronger correlation with condition process, when pad with larger groove density and smaller pore size.