Effect of Modified Silica Abrasive Particles on Nanosized Particle Deposition in Final Polishing of Silicon Wafers

The silane coupling agent γ-aminopropyl triethoxysilane (APTS) and polyethylene oxide (PEO) are proposed to modify the SiO₂ abrasive particles for final polishing of silicon wafers. The effects of the modified silica abrasive particles on nanosized particle deposition, roughness, and removal rate of the silicon wafer are explored in detail. PEO is proved to be a potential modifying agent for controlling deposition of large particles (～410 nm diameter), leading to low roughness (R_a = 0.097 nm), and APTS is found to be effective in controlling deposition of both large and small particles (～410 and ～200 nm diameter, respectively), resulting in lower roughness (R_a = 0.054 nm).