Abstract: During polishing of a backside conductive layer, a sensor of an in-situ eddy current monitoring system is repeatedly swept across the substrate so that each respective sweep of the sensor generates a respective signal trace that includes a sequence of signal values. For each respective signal trace, the sequence of signal values is converted to a corresponding thickness trace that includes sequence of thickness values for different locations on the substrate, thus generating a sequence of thickness traces. For each respective thickness trace in the sequence of thickness traces, a plurality of minima in the respective thickness trace are identified. A sequence of layer thickness values over time is calculated based on the plurality of minima from the respective traces in the sequence of thickness traces. Conductive vias extend through the semiconductor wafer of the substrate to electrically connect the backside conductive layer to a front-side conductive layer.

Abstract: A chemical mechanical polishing apparatus includes a platen to support a polishing pad, a carrier head to hold a substrate such that a layer on the substrate contacts the polishing pad, an actuator that controls a radial position of the carrier head over the platen, an eddy current monitoring system, and a controller. The eddy current monitoring system includes a first plurality of eddy current sensors supported by the platen and arranged in a first ring at a first distance from an axis of rotation of the platen and a second plurality of eddy current sensors supported by the platen and arranged in a second ring at a larger second distance from the axis of rotation of the platen. The controller is configured to control the actuator such that the second plurality of sensors sweep only across an edge portion of the substrate held by the carrier head.

Abstract: A method for removing material from a substrate includes dispensing an abrasive slurry on a polishing pad, storing an indication of a relative charge on the abrasive agent, contacting a surface of a substrate to the polishing pad in the presence of the slurry, generating relative motion between the substrate and the polishing pad, measuring a removal rate for the substrate, comparing a the measured removal rate to a target removal rate and determining whether to increase or decrease the removal rate based on the comparison, determining whether to increase or decrease a temperature of an interface between the polishing pad and the substrate based on the indication of the relative charge of the abrasive agent and on whether to increase or decrease the removal rate, and controlling a temperature of the interface as determined to modify the removal rate.

Abstract: A body is brought into contact with a polishing pad of a polishing system, a polishing liquid is supplied to the polishing pad, relative motion between the body and the polishing pad is generated while the body contacts the polishing pad, a signal from an in-situ eddy current monitoring system during the relative motion while the body contacts the polishing pad, generating, and mechanical vibrations in the polishing system are detected based on a signal from the in-situ eddy current monitoring system.

Abstract: A body is brought into contact with a polishing pad of a polishing system, a polishing liquid is supplied to the polishing pad, relative motion between the body and the polishing pad is generated while the body contacts the polishing pad, a signal from an in-situ eddy current monitoring system during the relative motion while the body contacts the polishing pad, generating, and mechanical vibrations in the polishing system are detected based on a signal from the in-situ eddy current monitoring system.

Abstract: A polishing control technique includes storing data representing a sequence of background traces generated by a sequence of scans of a sensor of an in-situ monitoring system across a substrate, and polishing a layer on a substrate. The layer is monitored during the polishing with the in-situ monitoring system, including repeatedly sweeping the sensor of the in-situ monitoring system across substrate such that each sweep provides a measured trace. For each measured trace, a respective background trace that has an equivalent position in the sequence of background traces is subtracted from the measured trace to generate a modified trace, and a sequence of estimated thickness values is generated based on the modified traces. A polishing endpoint is detected or a polishing parameter is modified based on the sequence of estimated thickness values.

Abstract: A technique for acquiring reference traces includes measuring an angular orientation of a calibration substrate, rotating a carrier head and a platen to respective predetermined angular positions, and bringing the calibration substrate into contact with a polishing pad on the platen. The platen and the carrier head are rotated with the calibration substrate in contact with the polishing pad. The calibration substrate is monitored by sweeping a sensor of an in-situ monitoring system across the calibration substrate to generate a sequence of reference traces with each respective reference trace of the sequence of reference traces corresponding to a respective sweep of a sequence of sweeps by the sensor, and with each reference trace including a series of signal values. The sequence of reference traces is stored and each reference trace is labelled to distinguish an order of the reference traces within the sequence.

Abstract: A body is brought into contact with a polishing pad of a polishing system, a polishing liquid is supplied to the polishing pad, relative motion between the body and the polishing pad is generated while the body contacts the polishing pad, a signal from an in-situ eddy current monitoring system during the relative motion while the body contacts the polishing pad, generating, and mechanical vibrations in the polishing system are detected based on a signal from the in-situ eddy current monitoring system.

Abstract: A method for removing material from a substrate includes dispensing an abrasive slurry on a polishing pad, storing an indication of a relative charge on the abrasive agent, contacting a surface of a substrate to the polishing pad in the presence of the slurry, generating relative motion between the substrate and the polishing pad, measuring a removal rate for the substrate, comparing a the measured removal rate to a target removal rate and determining whether to increase or decrease the removal rate based on the comparison, determining whether to increase or decrease a temperature of an interface between the polishing pad and the substrate based on the indication of the relative charge of the abrasive agent and on whether to increase or decrease the removal rate, and controlling a temperature of the interface as determined to modify the removal rate.

Abstract: A method for removing material from a substrate includes dispensing an abrasive slurry on a polishing pad, storing an indication of a relative charge on the abrasive agent, contacting a surface of a substrate to the polishing pad in the presence of the slurry, generating relative motion between the substrate and the polishing pad, measuring a removal rate for the substrate, comparing a the measured removal rate to a target removal rate and determining whether to increase or decrease the removal rate based on the comparison, determining whether to increase or decrease a temperature of an interface between the polishing pad and the substrate based on the indication of the relative charge of the abrasive agent and on whether to increase or decrease the removal rate, and controlling a temperature of the interface as determined to modify the removal rate.