Slurry distribution device for chemical mechanical polishing

An apparatus for chemical mechanical polishing, comprising:

• a rotatable platen having a surface to support a polishing pad;
• a carrier head to hold a substrate in contact with the polishing pad;
• a polishing liquid distribution system, the polishing liquid distribution system including
• a dispenser positioned to deliver a polishing liquid to a portion of a polishing surface of the polishing pad, and
• a first barrier spaced apart from the dispenser and positioned over the polishing surface before the portion of the polishing surface where the dispenser is to deliver the polishing liquid and configured to block used polishing liquid being carried on the polishing surface from reaching the portion of the polishing surface, wherein the first barrier includes a solid body having a portion with a leading surface to contact the used polishing liquid, wherein the portion of the first barrier that contacts the used polishing liquid curves about an axis perpendicular to the polishing surface.