During polishing of a stack of adjacent layers, a plurality of instances of a profile control algorithm are executed on a controller with different instances having different values for a control parameter. A first instance receives a sequence of characterizing values from an in-situ monitoring system during an initial time period to control a polishing parameter, and a second instance receives the sequence of characterizing values during the initial time period and a subsequent time period to control the polishing parameter. Exposure of the underlying layer is detected based on the sequence of characterizing values from the in-situ monitoring system.

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.

The present invention improves versatility of a film thickness measuring device. The trigger sensor 220 includes a proximity sensor 222 and a dog 224, and outputs a trigger signal indicating that a polishing table 110 makes one revolution. The eddy current sensor 210 measures a film thickness of a subject to be polished 102 at a timing based on the trigger signal output from the trigger sensor 220. The dog 224 is disposed in an opposite region 250 located at the opposite side of a rotation axis C.sub.W of the top ring 116 with respect to a rotation axis C.sub.T of the polishing table 110. Further, the eddy current sensor 210 and the proximity sensor 222 are disposed at the polishing table 110 so as to be located in the opposite region 250 when the trigger signal is output from the trigger sensor 220.

An eddy current sensor assembly includes an eddy current sensor and an output signal processing circuit that processes an output signal from the eddy current sensor. The output signal processing circuit includes a mixer circuit that accepts the output signal and a signal of the predetermined frequency as input, multiplies the two signals received as input, and outputs an output signal obtained by the multiplication, and a low-pass filter that accepts the output signal output by the mixer circuit as input, cuts a high-frequency signal included in the output signal received as input, and outputs at least a direct-current (DC) signal.

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.

To measure thickness in a polishing treatment more efficiently. A substrate polishing apparatus comprises a rotatably configured polishing table provided with a sensor that outputs a signal related to a thickness, a rotatably configured polishing head that faces the polishing table, a substrate being attachable to a face of the polishing head that faces the polishing table, and a controller. The controller acquires a signal from the sensor when the sensor passes over a surface to be polished of the substrate, specifies an orbit of the sensor with respect to the substrate on a basis of a profile of the signal, calculates a thickness of the substrate at each point on the orbit on a basis of the signal, and creates a thickness map on a basis of the calculated thickness at each point on a plurality of orbits of the sensor.

A method of controlling polishing includes polishing a stack of adjacent conductive layers on a substrate, measuring with an in-situ eddy current monitoring system a sequence of characterizing values for the substrate during polishing, calculating a polishing rate from the sequence of characterizing values repeatedly during polishing, calculating one or more adjustments for one or more polishing parameters based on a current polishing rate using a first control algorithm for an initial time period, detecting a change in the polishing rate that indicates exposure of the underlying conductive layer, and calculating one or more adjustments for one or more polishing parameters based on the polishing rate using a different second control algorithm for a subsequent time period after detecting the change in the polishing rate.

A method of controlling polishing includes sweeping a sensor of an in-situ monitoring system across a substrate as a layer of the substrate undergoes polishing, generating from the in-situ monitoring system a sequence of signal values that depend on a thickness of the layer, detecting from the sequence of signal values, a time that the sensor traverses a leading edge of the substrate or a retaining ring and a time that the sensor traverses a trailing edge of the substrate or retaining ring; and for each signal value of at least some of the sequence of signal values, determining a position on the substrate for the signal value based on the time that the sensor traverses the leading edge and the time that the sensor traverses a trailing edge.

The eddy current sensor for measuring the film thickness of a conductive film formed on a substrate includes a core made of a magnetic material that has a base portion, and outer legs provided to the base portion at both end portions in a first direction of the base portion respectively, an excitation coil that is arranged on the core and forms an eddy current in the conductive film, and a detection coil that is arranged on the core and detects the eddy current formed in the conductive film. The length of the base portion in the first direction is not less than the length of the base portion in a second direction that is substantially orthogonal to the first direction.

A polishing apparatus comprises a dresser that can adjust swing speed in the scanning areas set on a polishing member along a swing direction, a height detection section that measures a surface height of the polishing member in a plurality of monitoring areas set on the polishing member along the swing direction of the dresser, a dress model matrix creation section that creates a dress model matrix defined from a plurality of monitoring areas, scanning areas and a dress model, an evaluation index creation section that calculates a height profile predicted value using the dress model, the swing speed in each scanning area or a staying time and sets evaluation index based on a difference from a target value of height profile of the polishing member and a moving speed calculation section that calculates the swing speed in each scanning area of the dresser based on the evaluation index.