Constant pH polish and scrub

摘要

A system and method are provided that maintains a high pH at the wafer surface through the entire polish process and then lowers the pH only when necessary in a controlled fashion after CMP and during the post-polish clean. A fluid having a high pH chemistry and, optionally, surfactants is used instead of deionized water to keep the wafer and polisher components wet and to clean the slurry residue from the polishing pad.