Abstract: A method of polishing a layer on the substrate at a polishing station includes the actions of monitoring the layer during polishing at the polishing station with an in-situ monitoring system to generate a plurality of measured signals for a plurality of different locations on the layer; generating, for each location of the plurality of different locations, an estimated measure of thickness of the location, the generating including processing the plurality of measured signals through a neural network; and at least one of detecting a polishing endpoint or modifying a polishing parameter based on each estimated measure of thickness.

Abstract: A method to assist in identifying a spectral feature and a characteristic of the selected spectral feature to monitor during polishing includes polishing a test substrate and measuring a sequence of spectra of light reflected from a substrate while the substrate is being polished, where at least some of the spectra of the sequence differ due to material being removed during the polishing. The sequence of spectra are visually displayed as a contour plot.

Abstract: 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.

Abstract: A method of chemical mechanical polishing includes bringing a substrate having a conductive layer disposed over a semiconductor wafer into contact with a polishing pad, generating relative motion between the substrate and the polishing pad, monitoring the substrate with an in-situ electromagnetic induction monitoring system as the conductive layer is polished to generate a sequence of signal values that depend on a thickness of the conductive layer, determining a sequence of thickness values for the conductive layer based on the sequence of signal values, and at least partially compensating for a contribution of conductivity of the semiconductor wafer to the signal values.

Abstract: Data received from an in-situ monitoring system includes, for each scan of a sensor, a plurality of measured signal values for a plurality of different locations on a layer. A thickness of a polishing pad is determined based on the data from the in-situ monitoring system. For each scan, a portion of the measured signal values are adjusted based on the thickness of the polishing pad. For each scan of the plurality of scans and each location of the plurality of different locations, a value is generated representing a thickness of the layer at the location. This includes processing the adjusted signal values using one or more processors configured by machine learning. A polishing endpoint is detected or a polishing parameter is modified based on the values representing the thicknesses at the plurality of different locations.

Abstract: 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.

Abstract: A method of polishing a layer on the substrate at a polishing station includes the actions of monitoring the layer during polishing at the polishing station with an in-situ monitoring system to generate a plurality of measured signals for a plurality of different locations on the layer; generating, for each location of the plurality of different locations, an estimated measure of thickness of the location, the generating including processing the plurality of measured signals through a neural network; and at least one of detecting a polishing endpoint or modifying a polishing parameter based on each estimated measure of thickness.

Abstract: A method to assist in identifying a spectral feature and a characteristic of the selected spectral feature to monitor during polishing includes polishing a test substrate and measuring a sequence of spectra of light reflected from a substrate while the substrate is being polished, where at least some of the spectra of the sequence differ due to material being removed during the polishing. The sequence of spectra are visually displayed as a contour plot.

Abstract: An apparatus for chemical mechanical polishing includes a platen having a surface to support a polishing pad, a carrier head to hold a substrate against a polishing surface of the polishing pad, a pad conditioner including a conductive body to be pressed against the polishing surface, an in-situ polishing pad thickness monitoring system including a sensor disposed in the platen to generate a magnetic field that passes through the polishing pad, and a controller configured to receive a signal from the monitoring system and generate a measure of polishing pad thickness based on a portion of the signal corresponding to a time that the sensor is below the conductive body of the pad conditioner.

Abstract: In one aspect, a method of polishing includes polishing a substrate, and receiving an identification of a selected spectral feature and a characteristic of the selected spectral feature to monitor during polishing. The method includes measuring a sequence of spectra of light reflected from the substrate while the substrate is being polished, where at least some of the spectra of the sequence differ due to material being removed during the polishing. The method of polishing includes determining a value of a characteristic of the selected spectral feature for each of the spectra in the sequence of spectra to generate a sequence of values for the characteristic, fitting a function to the sequence of values, and determining either a polishing endpoint or an adjustment for a polishing rate based on the function.

Abstract: A method of controlling polishing includes polishing a substrate and receiving an identification of a selected spectral feature, a wavelength range having a width, and a characteristic of the selected spectral feature to monitor during polishing. A sequence of spectra of light from the substrate is measured while the substrate is being polished. A sequence of values of the characteristic of the selected spectral feature is generated from the sequence of spectra. For at least some spectra from the sequence of spectra, a modified wavelength range is generated based on a position of the spectral feature within a previous wavelength range used for a previous spectrum in the sequence of spectra, the modified wavelength range is searched for the selected spectral feature, and a value of a characteristic of the selected spectral feature is determined.

Abstract: A computer-implemented method of generating reference spectra includes polishing a first substrate in a polishing apparatus having a rotatable platen, measuring a sequence of spectra from the substrate during polishing with an in-situ monitoring system, associating each spectrum in the sequence of spectra with a index value equal to a number of platen rotations at which the each spectrum was measured, and storing the sequence of spectra as reference spectra.

Abstract: A method of controlling polishing includes polishing a region of a substrate at a first polishing rate, measuring a sequence of characterizing values for the region of the substrate during polishing with an in-situ monitoring system, determining a polishing rate adjustment for each of a plurality of adjustment times prior to a polishing endpoint time, and adjusting a polishing parameter to polish the substrate at a second polishing rate. The time period is greater than a period between the adjustment times and the projected time is before the polishing endpoint time. The second polishing rate is the first polishing rate as adjusted by the polishing rate adjustment.

Abstract: A computer-implemented method of generating reference spectra includes polishing a first substrate in a polishing apparatus having a rotatable platen, measuring a sequence of spectra from the substrate during polishing with an in-situ monitoring system, associating each spectrum in the sequence of spectra with a index value equal to a number of platen rotations at which the each spectrum was measured, and storing the sequence of spectra as reference spectra.

Abstract: A method of controlling polishing includes polishing a region of a substrate at a first polishing rate, measuring a sequence of characterizing values for the region of the substrate during polishing with an in-situ monitoring system, determining a polishing rate adjustment for each of a plurality of adjustment times prior to a polishing endpoint time, and adjusting a polishing parameter to polish the substrate at a second polishing rate. The time period is greater than a period between the adjustment times and the projected time is before the polishing endpoint time. The second polishing rate is the first polishing rate as adjusted by the polishing rate adjustment.

Abstract: A method of controlling polishing includes polishing a region of a substrate at a first polishing rate, measuring a sequence characterizing values for the region of the substrate during polishing with an in-situ monitoring system, determining a polishing rate adjustment for each of a plurality of adjustment times prior to a polishing endpoint time, and adjusting a polishing parameter to polish the substrate at a second polishing rate. The time period is greater than a period between the adjustment times and the projected time is before the polishing endpoint time. The second polishing rate is the first polishing rate as adjusted by the polishing rate adjustment.

Abstract: A method of controlling processing of a substrate includes measuring a spectrum reflected from the substrate, for each partition of a plurality of partitions of the measured spectrum, computing a partition value based on the measured spectrum within the partition to generate a plurality of partition values, for each reference spectrum signature of a plurality of reference spectrum signatures, determining a membership function for each partition, for each partition, computing a membership value based on the membership function for the partition and the partition value for the partition to generate a plurality of groups of membership values with each group of the plurality of groups associated with a reference spectrum signature, selecting a best matching reference spectrum signature from the plurality of reference spectra signatures based on the plurality of groups of membership values, and determining a characterizing value associated with the best matching reference spectrum signature.

Abstract: A measured characterizing value dependent on a thickness of a region of a substrate is input into a first predictive filter. The first predictive filter generates a filtered characterizing value. A measured characterizing rate at which the measured characterizing value changes is input into a second predictive filter. The second predictive filter generates a filtered characterizing rate of the region of the substrate. The measured characterizing value and the measured characterizing rate are determined based on in-situ measurements made at or before a first time during a polishing process of the substrate. A desired characterizing rate is determined to be used for polishing the region of the substrate after the first time and before a second, later time based on the filtered characterizing value and the filtered characterizing rate.

Abstract: A computer-implemented method includes receiving a sequence of current spectra of reflected light from a substrate; comparing each current spectrum from the sequence of current spectra to a plurality of reference spectra from a reference spectra library to generate a sequence of best-match reference spectra; determining a goodness of fit for the sequence of best-match reference spectra; and determining at least one of whether to adjust a polishing rate or an adjustment for the polishing rate, based on the goodness of fit.

Abstract: A method of controlling polishing includes polishing a substrate and receiving an identification of a selected spectral feature, a wavelength range having a width, and a characteristic of the selected spectral feature to monitor during polishing. A sequence of spectra of light from the substrate is measured while the substrate is being polished. A sequence of values of the characteristic of the selected spectral feature is generated from the sequence of spectra. For at least some spectra from the sequence of spectra, a modified wavelength range is generated based on a position of the spectral feature within a previous wavelength range used for a previous spectrum in the sequence of spectra, the modified wavelength range is searched for the selected spectral feature, and a value of a characteristic of the selected spectral feature is determined.