Patent ID: 7001246
Filing Date: 2006-02-21
Classification: B24B,G01B

Abstract:
1. A polishing system, comprising: a polishing pad having a polishing surface, a bottom surface, a cover layer, and a backing layer, the polishing pad including a recess formed in the bottom surface, wherein the recess includes an aperture formed in the backing layer, and wherein the recess includes an indentation formed in a bottom surface of cover layer and aligned with the aperture in the backing layer; a carrier operable to hold a substrate against the polishing surface of the polishing pad; a motor operable to cause relative motion between the polishing pad and the substrate; and an eddy current monitoring system including a ferromagnetic body positioned on a side of the polishing surface opposite the substrate, the ferromagnetic body extending into the recess and at least partially through the polishing pad, the eddy current monitoring system being operable to monitor a magnetic field using an induction coil that is magnetically coupled to the ferromagnetic body.