Effect of Pad Pore Size and Applied Pressure on Environmentally Friendly Buff Cleaning Using Gas-Dissolved Water for Ceria Nanoparticle Removal

This study investigates an environmentally friendly buff cleaning technique aimed at removing ceria nanoparticles remaining after chemical mechanical planarization (CMP), a critical step in semiconductor fabrication where post-cleaning is essential to prevent yield loss caused by particle contamination. Gas-dissolved water (GDW), prepared by dissolving CO₂ or N₂ into DI water, was utilized to generate micro-and nanobubbles that assist in particle detachment through physical interaction and electrostatic attraction. Among the tested conditions, CO₂ GDW demonstrated superior cleaning performance due to its higher bubble density and enhanced interfacial activity. Additionally, the use of larger-pore polyurethane pads and low-pressure conditions further improved cleaning efficiency by promoting fluid exchange and sustaining bubble–particle interactions. These findings highlight the potential of GDW as a safe, effective, and sustainable alternative to conventional chemical-based post-CMP cleaning solutions.