Patent ID: 8128461

Claim:
A chemical-mechanical polishing apparatus for polishing a workpiece, the apparatus comprising: a polishing pad having a polishing surface configured to engage the workpiece, wherein the polishing pad comprises a plurality of fluid delivery zones including a first fluid delivery zone and a second fluid delivery zone; and a platen mechanically supporting the polishing pad from a side of the polishing pad opposite the polishing surface and providing fluid to each of the fluid delivery zones, wherein the platen comprises a common fluid source and a plurality of fluid distribution layers each arranged in parallel with the other fluid distribution layers and with the polishing pad, wherein the plurality of fluid distribution layers comprises: a first fluid-distribution layer having a first fluid-distributing channel extending from the common fluid source to a first distribution point on the first fluid distribution layer that corresponds to the first fluid-delivery zone on the polishing pad; and a second fluid-distribution layer located between the first fluid-distribution layer and the polishing pad, the second fluid-distribution layer having a second fluid-distributing channel extending from the common fluid source to a second distribution point on the second fluid distribution layer that corresponds to the second fluid delivery zone on the polishing pad that is different from the first fluid delivery zone, and wherein the second layer comprises at least one hole that allows fluid from the first distribution point on the first fluid-distribution layer to pass through the second fluid-distribution layer toward the first fluid delivery zone on the polishing pad.