An apparatus for chemical mechanical polishing includes a platen having a surface to support a polishing pad and an electromagnetic induction monitoring system to generate a magnetic field to monitor a substrate being polished by the polishing pad. The electromagnetic induction monitoring system includes a core positioned at least partially in the platen and a coil wound around a portion of the core. The core includes a back portion and a multiplicity of posts extending from the back portion in a first direction normal to the surface of the platen. The core and coil are configured such that the multiplicity of posts include a first plurality of posts to provide a first magnetic polarity and a second plurality of posts to provide an opposite second magnetic polarity, and the first plurality of posts and the second plurality of posts are arranged in an alternating pattern.

An apparatus for chemical mechanical polishing includes a support for a polishing pad having a polishing surface, and an electromagnetic induction monitoring system to generate a magnetic field to monitor a substrate being polished by the polishing pad. The electromagnetic induction monitoring system includes a core and a coil wound around a portion of the core. The core includes a back portion, a center post extending from the back portion in a first direction normal to the polishing surface, and an annular rim extending from the back portion in parallel with the center post and surrounding and spaced apart from the center post by a gap. A width of the gap is less than a width of the center post, and a surface area of a top surface of the annular rim is at least two times greater than a surface area of a top surface of the center post.

The invention relates to improved systems and methods for inspecting the tubes of a steam generator of a nuclear reactor that involves modeling the steam generator, comparing signals of a tube from an eddy current sensor with aspects of the model to determine whether further analysis is required, employing primary and secondary analysis processes, and producing a combined report of the primary and secondary analysis results.

A method of controlling processing of a substrate includes generating, based on a signal from an in-situ monitoring system, first and second sequences of characterizing values indicative of a physical property of a reference zone and a control zone, respectively, on a substrate. A reference zone rate and a control zone rate are determined from the first and sequence of characterizing values, respectively. An error value is determined by comparing characterizing values for the reference zone and control zone. An output parameter value for the control zone us generated based on at least the error value and a dynamic nominal control zone value using a proportional-integral-derivative control algorithm, and the dynamic nominal control zone value is generated in a second control loop based on at least the reference zone rate and the control zone rate. The control zone of the substrate is processed according to the output parameter value.

In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system, comprises determining an orientation of a substrate relative to a first carrier head. The method further includes initiating a polishing process of a surface of the substrate engaged with a polishing pad. The method further includes scanning, during the polishing process, a first portion of the surface of the substrate repeatedly using at least one endpoint sensor coupled to the polishing pad to generate orientation dependent scan data of a property of the first portion of the surface. The method further includes comparing the orientation dependent scan data to a library of orientation dependent scan data to determine when the endpoint of the polishing process has been reached.

A method of polishing a substrate includes polishing a conductive layer on the substrate at a polishing station, monitoring the layer with an in-situ eddy current monitoring system to generate a plurality of measured signals values for a plurality of different locations on the layer, generating thickness measurements the locations, and detecting a polishing endpoint or modifying a polishing parameter based on the thickness measurements. The conductive layer is formed of a first material having a first conductivity. Generating includes calculating initial thickness values based on the plurality of measured signals values and processing the initial thickness values through a neural network that was trained using training data acquired by measuring calibration substrates having a conductive layer formed of a second material having a second conductivity that is lower than the first conductivity to generated adjusted thickness values.

Eddy current formable in a polishing target is detected as an impedance by an eddy current sensor. A resistance component and a reactance component of the impedance are associated with respective axes of a coordinate system having orthogonal axes, respectively. An angle calculator calculates the tangent of an intersection angle between a first straight line connecting a first point corresponding to an impedance for a zero film thickness, and a second point corresponding to an impedance for a non-zero film thickness, and a diameter of a circle passing through the first point. A film thickness calculator determines the film thickness from the tangent.

A receiving unit receives sensor data output from an eddy current sensor for detecting the film thickness of a polishing object to generate film thickness data. A correcting unit corrects the film thickness data in an inside of the edge of the polishing object based on the film thickness data generated by the receiving unit. The correcting unit corrects the film thickness data generated by the receiving unit in the inside of the edge of the polishing object using the film thickness data generated by the receiving unit in an outside of the edge of the polishing object.

An eddy current sensor has an exciting coil and a detection coil. A holding circuit holds reference data indicating a characteristic of an output signal output from the detection coil at a reference state and outputs the reference data at a state other than the reference state. A pseudo signal generating circuit generates and outputs a balance coil pseudo signal corresponding to the output signal output from the detection coil at the reference state from the reference data output from the holding circuit. A bridge circuit, at the state other than the reference state, receives the output signal output from the detection coil and the balance coil pseudo signal and outputs a bridge output signal corresponding to a difference between the output signal and the balance coil pseudo signal as a bridge output signal.

Provided is an eddy current sensor having an improved sensitivity in a detection coil of the eddy current sensor compared with a conventional one. An eddy current sensor (210) includes a magnetic material, a detection coil (34), a correction coil (166), and an excitation coil. The excitation coil is wound to surround the first pillar and/or the external wall of the magnetic material and generates an eddy current in a conductive film. The detection coil (34) and the correction coil (166) are wound to surround the first pillar and/or the external wall and detects a change in the eddy current generated in the conductive film. An amount of change in an output signal of the correction coil (166) when the eddy current generated in the conductive film changes is less than an amount of change in an output signal of the detection coil (34). One end of the correction coil (166) is directly connected to one end of the detection coil (34), and another end of the correction coil and another end of the detection coil are directly connected to an impedance converter (124) or an amplifier.