Method of determining pressure to apply to wafers during a cmp

A system configured to uniformly planarize a wafer, comprising:

• a wafer planarization machine having a plurality of pressure regions that correspond to a plurality of zones of the wafer, the wafer planarization machine including:
• a detection device configured to determine a first wafer warped value at a first zone of the wafer and a second wafer warped value at a second zone of the wafer;
• a processor coupled to the detection device and configured to determine a pressure difference based on the first and second wafer warped values from the first and second zones on the wafer;
• and
• a controller coupled to the processor and configured to apply a first pressure with a first pressure region to a first zone of the wafer and a second pressure with a second pressure region to a second zone of the wafer during a chemical mechanical planarization, wherein a difference between the first pressure and the second pressure corresponds to the pressure difference.

A method, comprising:

• determining a first warp value for a wafer at a zone away from the wafer center, Li;
• determining a second warp value for the wafer at the wafer center, L0;
• determining a curvature at the zone of the first warp value;
• applying pressure to the wafer during a chemical-mechanical planarization using the first and second warp values in accordance with the following formula:
• P0−Pi=k1*ci*(L0−Li)
• wherein
• Pi represents the pressure applied where the warp length is Li;
• P0 represents the pressure applied at the wafer center;
• k1 represents a film dependent constant;
• and
• ci represents an absolute value of the curvature where the warp length is Li.