Nano size cerium hydroxide slurry for scratch-free CMP process

We report recent progress in a novel cerium hydroxide polishing slurry with particle size of about 5 nm nano size cerium hydroxide (NSC) abrasive. NSC has succeeded in omitting particles over 1 μm, and in reducing scratches to 1/30 of those with calcined ceria slurry. Even though, NSC maintains oxide removal rate similar to conventional ceria. Mixing NSC with the specific additives brought out tunable polishing of SiO 2 , SiN, and poly-Si.