EDDY CURRENT SENSOR WITH ENHANCED EDGE RESOLUTION

摘要

An apparatus for monitoring the thickness of a conductive layer on a substrate includes a support to hold a substrate having a conductive layer, an eddy current monitoring system including a first plurality of core portions, and a motor to cause relative motion between the support and the eddy current monitoring system such that the substrate moves across the first plurality of core portions in a direction that defines a first axis. At least one core portion is positioned further from a second axis than at least two other core portions. The second axis is orthogonal to the first axis.