Chemical mechanical polishing apparatus
View Patent ↗Disclosed is a chemical mechanical polishing apparatus for polishing a surface of a wafer using a mechanical friction as well as a chemical polishing agent. The chemical mechanical polishing apparatus includes a polishing head for absorbing a wafer and a polishing means for polishing the wafer. The polishing apparatus may include a platen composed of at least three segments formed in conformity with polishing zones, a polishing pad provided on each of the segments, and a support for supporting the segments such that the segments are separately adjustable in the height depending on the polishing zones and are rotatable.
1. A chemical mechanical polishing apparatus comprising:
a platen comprising a center polishing zone containing a rotatable circular segment with a first rod having an independently adjustable height, an edge polishing zone containing a first rotatable ring-shaped segment with a second rod having an independently adjustable height and a middle polishing zone between the edge polishing zone and the center polishing zone, containing a second rotatable ring-shaped segment with a third rod having an independently adjustable height, and
a polishing pad on the platen.
2. A chemical mechanical polishing apparatus as defined by claim 1 , further comprising slurry supply nozzles between the segments.
3. A chemical mechanical polishing apparatus as defined by claim 1 , further comprising slurry supply nozzles passing through the center of the segments.
4. A chemical mechanical polishing apparatus as defined by claim 3 , wherein the slurry is dispensed through holes in the polishing pad.
5. A chemical mechanical polishing apparatus as defined by claim 1 , further comprising a polishing head.
6. A chemical mechanical polishing apparatus as defined by claim 5 , wherein the polishing head comprises a membrane which contacts a backside of a wafer.
7. A chemical mechanical polishing apparatus as defined by claim 6 , wherein the membrane is adapted to apply a force to the backside of the wafer.
8. A chemical mechanical polishing apparatus as defined by claim 1 , further comprising a support under the platen.
9. A chemical mechanical polishing apparatus as defined by claim 1 , wherein the polishing pad comprises separate zone polishing pads on each segment.
10. A chemical mechanical polishing apparatus as defined by claim 1 , wherein the independently adjustable heights of the segments allow applying a uniform pressure to a surface of a wafer.
11. A chemical mechanical polishing apparatus as defined by claim 5 , further comprising fluid supply holes in the polishing head to supply compressed air to a side of the membrane.