During chemical mechanical polishing of a substrate, a signal value that depends on a thickness of a layer in a measurement spot on a substrate undergoing polishing is determined by a first in-situ monitoring system. An image of at least the measurement spot of the substrate is generated by a second in-situ imaging system. Machine vision processing, e.g., a convolutional neural network, is used to determine a characterizing value for the measurement spot based on the image. Then a measurement value is calculated based on both the characterizing value and the signal value.

During chemical mechanical polishing of a substrate, a signal value that depends on a thickness of a layer in a measurement spot on a substrate undergoing polishing is determined by a first in-situ monitoring system. An image of at least the measurement spot of the substrate is generated by a second in-situ imaging system. Machine vision processing, e.g., a convolutional neural network, is used to determine a characterizing value for the measurement spot based on the image. Then a measurement value is calculated based on both the characterizing value and the signal value.

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 to hold a conditioning disk against the polishing surface, an in-situ polishing pad thickness monitoring system, and a controller. The controller is configured to store data associating each of a plurality of conditioner disk products with a respective threshold value, receive an input selecting a conditioner disk product from the plurality of conditioner disk products, determine a particular threshold value associated with the selected conditioner disk product, receive a signal from the monitoring system, generate a measure of a pad cut rate from the signal, and generate an alert if the pad cut rate falls beyond the particular threshold value.

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 to hold a conditioning disk against the polishing surface, an in-situ polishing pad thickness monitoring system, and a controller. The controller is configured to store data associating each of a plurality of conditioner disk products with a respective threshold value, receive an input selecting a conditioner disk product from the plurality of conditioner disk products, determine a particular threshold value associated with the selected conditioner disk product, receive a signal from the monitoring system, generate a measure of a pad cut rate from the signal, and generate an alert if the pad cut rate falls beyond the particular threshold value.

An apparatus for chemical mechanical polishing of a wafer includes a process chamber and a rotatable platen disposed inside the process chamber. A polishing pad is disposed on the platen and a wafer carrier is disposed on the platen. A slurry supply port is configured to supply slurry on the platen. A process controller is configured to control operation of the apparatus. A set of microphones is disposed inside the process chamber. The set of microphones is arranged to detect sound in the process chamber during operation of the apparatus and transmit an electrical signal corresponding to the detected sound. A signal processor is configured to receive the electrical signal from the set of microphones, process the electrical signal to enable detection of an event during operation of the apparatus, and in response to detecting the event, transmit a feedback signal to the process controller. The process controller is further configured to receive the feedback signal and initiate an action based on the received feedback signal.

An apparatus for chemical mechanical polishing of a wafer includes a process chamber and a rotatable platen disposed inside the process chamber. A polishing pad is disposed on the platen and a wafer carrier is disposed on the platen. A slurry supply port is configured to supply slurry on the platen. A process controller is configured to control operation of the apparatus. A set of microphones is disposed inside the process chamber. The set of microphones is arranged to detect sound in the process chamber during operation of the apparatus and transmit an electrical signal corresponding to the detected sound. A signal processor is configured to receive the electrical signal from the set of microphones, process the electrical signal to enable detection of an event during operation of the apparatus, and in response to detecting the event, transmit a feedback signal to the process controller. The process controller is further configured to receive the feedback signal and initiate an action based on the received feedback signal.

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.

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.

A chemical mechanical polishing apparatus includes a platen to support a polishing pad, the platen having a recess, a flexible membrane in the recess, and an in-situ vibration monitoring system to generate a signal. The in-situ acoustic monitoring system includes a vibration sensor supported by the flexible membrane and positioned to couple to an underside of the polishing pad.

A chemical mechanical polishing apparatus includes a platen to support a polishing pad, the platen having a recess, a flexible membrane in the recess, and an in-situ vibration monitoring system to generate a signal. The in-situ acoustic monitoring system includes a vibration sensor supported by the flexible membrane and positioned to couple to an underside of the polishing pad.