Promotive Effect of Organic Acids on the Dispersion of Ceria Slurry and the Removal Rate of TEOS in Chemical Mechanical Polishing

In this study, the effect of organic acids (formic acid, acetic acid, and lactic acid) on the material removal rate (MRR) of TEOS films was investigated. The results showed that formic acid was an effective dispersant for CeO 2 slurry. When adding formic acid to the slurry, the average particle size of CeO 2 was reduced to 172.5 nm and the Zeta potential was increased to 47.6 mV. Consequently, the MRR of TEOS improved from 408.3 to 695.5 nm min −1 with a surface roughness of 0.16 nm. The MRR of the pattern wafer was increased from 575.1 to 941.6 nm min −1 . Molecular dynamics simulation indicated that the oxygen atom attached to the double bond in the carboxyl group serves as the primary electrophilic reaction site. The double electric layer was thickest between formic acid and CeO 2 , resulting in the best dispersion of CeO 2 slurry, which was conducive to improving the MRR of TEOS. The polishing effect of formic acid was verified by adding polyethylene glycol, enhancing the MRR of TEOS was 1351.2 nm min −1 .