Post Cleaning For Feol Cmp With Silica And Ceria Slurries

Post cleaning experiments for FEOL CMP with silica and ceria slurries are carried out on commercial polishers with 300mm wafers. Considering the potential charge attraction or repulsion between particles and wafer surface, clean chemicals, acidic and basic, are applied at different stages of the post CMP process sequence. Diluted hydrogen peroxide in a non-contact megasonic cleaner is used to remove ceria abrasive particles with high efficiency. On-platen buff clean with or without pad conditioning can make an impact on the post CMP cleaning performance.