Novel CMP slurry for polishing silicon containing materials

In this paper we will report a novel CMP slurry chemistry which can provide tunable removal selectivity between various silicon-containing materials, such as SiGe, bare silicon, poly silicon or amorphous silicon against SiO₂ and/or SiN. The slurry chemistry is a non-hydrogen peroxide based system containing a novel catalyst. By adjusting the amount of the catalyst, we can fine tune desirable removal selectivity. Moreover, the novel catalyst can act either as a removal rate inhibitor or an enhancer for silicon removal rate depending on the alkalinity of slurry. At lower pH, it inhibits silicon RR as its dosage is increased; at higher pH, it flips, becoming an enhancer for silicon removal. Same tendency is revealed for poly-silicon and amorphous silicon, too. The novel catalyst does not impact on removal rate of TEOS or SiN, but on SiGe. The higher dosage of the novel catalyst the higher removal rate of SiGe becomes. Furthermore, the slurry has zero corrosion/etching rate on silicon containing materials.