Method and apparatus of eddy current monitoring for chemical mechanical polishing

摘要

A polishing system can have a rotatable platen, a polishing pad secured to the platen, a carrier head to hold a substrate against the polishing pad, and an eddy current monitoring system including a coil or ferromagnetic body that extends at least partially through the polishing pad. A polishing pad can have a polishing layer and a coil or ferromagnetic body secured to the polishing layer. Recesses can be formed in a transparent window in the polishing pad.