Particles Manipulation to Improve Removal Efficiency of Fused Silica in Chemical Mechanical Polishing

SiO 2 based slurry was an ideal solution for addressing element pollution in fused silica polishing. However, it was still a huge challenge to enhance polishing efficiency. Herein, lignin was added into colloidal silica to manipulate SiO 2 particles, thereby improving the removal efficiency of fused silica. Specifically, the variations of average particle size ( Z -Average) and polymer dispersity index ( PDI ), -OH groups on particles surface, wettability and viscosity of colloidal silica with addition lignin in the range of 0–5% were introduced. Also, adhesion action and tribological characteristics with and without manipulation in polishing process were studied. Removal mechanism of fused silica using SiO 2 based slurry and the key factors to improve polishing performance were discussed at different content of lignin. Colloidal silica was stable at lignin content of 2%, at which material removal rate ( MRR ) was increased by 216% and surface roughness ( Ra ) achieved 0.118 nm. This study embarked from abrasives variations directly (particles characteristics) and indirectly (colloidal silica) intending to reveal the change of removal mechanism on fused silica polishing. It provided new insights for fused silica polishing definitely.