Patent attributes
A wafer carrier for controlling downward force and edge effect during chemical mechanical planarization. A retaining ring actuator is disposed within the retaining ring to control the height of the retaining ring relative to the bottom surface of the wafer carrier. An inflatable membrane is disposed across the bottom surface of the wafer carrier such that pressure in the bladder is independently regulated to control the downward force acting on the wafer during CMP. In addition, an edge control bladder may also be disposed within the carrier such that if the pressure in the bladder is also regulated, the amount of force on the edge of the wafer changes. By regulating retaining ring actuator pressure, inflatable membrane pressure, and edge control bladder pressure, non-uniformities in the wafer surface and edge effect may be addressed during CMP.
