Patent ID: 8739806

Claim:
A chemical mechanical polishing (CMP) system, comprising: a wafer polishing unit comprising a waste liquid sink for receiving a used slurry a waste slurry drain piping for draining the used slurry, a platen, a polishing pad mounted on the platen, a carrier for holding and rotating a wafer, and a slurry feeding device; and a post-CMP cleaning unit externally coupled to the wafer polishing unit, wherein the post-CMP cleaning unit comprises a waste liquid sink that is connected to the waste liquid sink of the wafer polishing unit through a conduit that guides a used base chemical from the post-CMP cleaning unit to flow toward the wafer polishing unit to wash at least the waste slurry drain piping every time the post-CMP cleaning unit is operated, and the post-CMP cleaning unit further comprises a plurality of rollers for supporting and rotating a wafer, a brush for scrubbing the wafer, and a spray bar disposed in proximity to the brush.