Patent ID: 6937915

Claim:
A system for detecting properties on a surface of a wafer, the system comprising: a wafer carrier head having a wafer mounting surface and at least one aperture extending therein away from the wafer mounting surface; and a sensor received in the aperture for response to energy transmitted past the wafer mounting surface and transmitted into the aperture; wherein the sensor is configured to respond to the energy in the form of induced eddy current having an aggregate value related to the properties on the surface of the wafer, wherein the properties on the surface of the wafer include a metallization pattern and a blanket metallization overburden, the aggregate value being composed of a first value representing a property of the blanket metallization overburden and a second value representing a property of the metallization pattern, and wherein the sensor is configured to output a signal having the second value and representing a status during wafer processing in which the blanket metallization overburden is cleared from the metallization pattern.