Eddy current sensor with enhanced edge resolution
AssigneeApplied Materials, Inc.
InventorsHassan G. Iravani, Ingemar Carlsson, Boguslaw A. Swedek
Life of this patent
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Abstract
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.
Claims22
An apparatus for monitoring a thickness of a conductive layer on a substrate, comprising:
- a support configured to hold the substrate with a face of the substrate in a first plane during monitoring;
- 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 first plurality of core portions move relative to the substrate in a first direction parallel to the first plane;
- wherein the first plurality of core portions are spaced apart in a second direction and separated by gaps, the second direction parallel to the first plane and perpendicular to the first direction, and
- wherein at least one core portion of the first plurality of core portions is positioned a different distance in the first direction from a first reference line than at least two other core portions, the first reference line being parallel to the first plane and orthogonal to the first direction.
Dependencies are inferred from the claim text.