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 metrology system for obtaining a measurement representative of a thickness of a layer on a substrate includes a camera positioned to capture a color image of at least a portion of the substrate. A controller is configured to receive the color image from the camera, store a predetermined path in a coordinate space of at least two dimension including a first color channel and a second color channel, store a function that provides a value representative of a thickness as a function of a position on the predetermined path, determine a coordinate of a pixel in the coordinate space from color data in the color image for the pixel, determine a position of a point on the predetermined path that is closest to the coordinate of the pixel, and calculate a value representative of a thickness from the function and the position of the point on the predetermined path.

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: In fabrication of an integrated circuit having a layer with a plurality of conductive interconnects, a layer of a substrate is polished to provide the layer of the integrated circuit. The layer of the substrate includes conductive lines to provide the conductive interconnects. The layer of the substrate includes a closed conductive loop formed of a conductive material in a trench. A depth of the conductive material in the trench is monitored using an inductive monitoring system and a signal is generated. Monitoring includes generating a magnetic field that intermittently passes through the closed conductive loop. A sequence of values over time is extracted from the signal, the sequence of values representing the depth of the conductive material over time.

Abstract: A method of polishing includes storing a predetermined location and a predetermined number as criteria for detecting an end point, polishing a substrate, measuring a sequence of current spectra of light reflected from the substrate while the substrate is being polished, identifying a plurality of peaks or valleys that persist with an evolving location through at least some of the sequence of current spectra, counting a number of peaks or valleys that were identified that pass the predetermined location as polishing progresses, and ceasing to polish the substrate when the number counted reaches the predetermined number.

Abstract: In fabrication of an integrated circuit having a layer with a plurality of conductive interconnects, a layer of a substrate is polished to provide the layer of the integrated circuit. The layer of the substrate includes conductive lines to provide the conductive interconnects. The layer of the substrate includes a closed conductive loop formed of a conductive material in a trench. A depth of the conductive material in the trench is monitored using an inductive monitoring system and a signal is generated. Monitoring includes generating a magnetic field that intermittently passes through the closed conductive loop. A sequence of values over time is extracted from the signal, the sequence of values representing the depth of the conductive material over time.

Abstract: A polishing system includes a polishing station including a platen to support a polishing pad, a support to hold a substrate, an in-line metrology station to measure the substrate before or after polishing of a surface of the substrate in the polishing station, and a controller. The in-line metrology station includes a color line-scan camera, a white light source, a frame supporting the light source and the camera, and a motor to cause relative motion between the camera and the support along a second axis perpendicular to the first axis to cause the light source and the camera to scan across the substrate. The controller is configured to receive a color data from the camera, to generate a 2-dimensional color image from the color data, and to control polishing at the polishing station based on the color image.

Abstract: A method of detecting a polishing endpoint includes storing a plurality of library spectra, measuring a sequence of spectra from the substrate in-situ during polishing, and for each measured spectrum of the sequence of spectra, finding a best matching library spectrum from the plurality of library spectra to generate a sequence of best matching library spectra. Each library spectrum has a stored associated value representing a degree of progress through a polishing process, and the stored associated value for the best matching library spectrum is determined for each best matching library spectrum to generate a sequence of values representing a progression of polishing of the substrate. The sequence of values is compared to a target value, and a polishing endpoint is triggered when the sequence of values reaches the target value.

Abstract: A method of polishing includes storing a predetermined location and a predetermined number as criteria for detecting an end point, polishing a substrate, measuring a sequence of current spectra of light reflected from the substrate while the substrate is being polished, identifying a plurality of peaks or valleys that persist with an evolving location through at least some of the sequence of current spectra, counting a number of peaks or valleys that were identified that pass the predetermined location as polishing progresses, and ceasing to polish the substrate when the number counted reaches the predetermined number.

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: Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra.

Abstract: A polishing system receives one or more target parameters for a selected peak in a spectrum of light, polishes a substrate, measures a current spectrum of light reflected from the substrate while the substrate is being polished, identifies the selected peak in the current spectrum, measures one or more current parameters of the selected peak in the current spectrum, compares the current parameters of the selected peak to the target parameters, and ceases to polish the substrate when the current parameters and the target parameters have a pre defined relationship.

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: During polishing of a first substrate at a first polishing station, a sequence of measurements by a first in-situ monitoring system is monitored to determining a first time at which the first sequence exhibits a first predefined feature indicating a predetermined thickness of an overlying layer, and during polishing of the first substrate at a second polishing station, a sequence of measurements by a second in-situ monitoring system is monitored to determine a second time indicating clearance of the overlying layer and exposure of the underlying layer. The first time is used to calculate a first adjusted polishing pressure for a second substrate at the first polishing station, and the second time is used to calculate a second adjusted polishing pressure for the second substrate at the second polishing station.

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 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 polishing apparatus includes a plurality of stations supported on a platform, the plurality of stations including at least two polishing stations and a transfer station, each polishing station including a platen to support a polishing pad, a plurality of carrier heads suspended from and movable along a track such that each polishing station is selectively positionable at the stations, and a controller configured to control motion of the carrier heads along the track such that during polishing at each polishing station only a single carrier head is positioned in the polishing station.

Abstract: A method of controlling polishing includes polishing a substrate, during polishing monitoring the substrate with an in-situ monitoring system, the monitoring including generating a signal from a sensor, and filtering the signal to generate a filtered signal. The signal includes a sequence of measured values, and the filtered signal including a sequence of adjusted values. The filtering includes for each adjusted value in the sequence of adjusted values, generating at least one predicted value from the sequence of measured values using linear prediction, and calculating the adjusted value from the sequence of measured values and the predicted value. At least one of a polishing endpoint or an adjustment for a polishing rate is determined from the filtered signal.

Abstract: A method of controlling polishing includes polishing a metal layer of a substrate. The metal layer overlies an underlying layer structure. During polishing of the metal layer, a light beam is directed onto the first substrate. The metal layer is sufficiently thin that a portion of the light beam reflects from an exposed surface of the metal layer and a portion of the light beam passes through the metal layer and reflects from the underlying layer structure to generate a reflected light beam. The reflected light beam is monitored during polishing and a sequence of measured spectra is generated from the reflected light beam. At least one of a polishing endpoint or an adjustment for a polishing rate is determined from the sequence of measured spectra.