Patent ID: 11966212
Assignee: APPLIED MATERIALS, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 18:
19. A polishing system, comprising:
a support to hold a polishing pad;
a carrier head to hold a substrate in contact with the polishing pad;
a motor to generate relative motion between the support and the carrier head;
an in-situ optical monitoring system to measure a spectrum of light reflected from the substrate during polishing; and
a controller configured to
receive, from the optical in-situ monitoring system, a measured spectrum of light reflected from the substrate undergoing polishing,
reduce a dimensionality of the measured spectrum to generate a plurality of component values using a transformation based on a plurality of reference spectra,
receive one or more values of one or more processing or environmental variables other than the plurality of component values,
for each scan of a plurality of scans, generate a value for a thickness for each scan of an outer layer of the substrate undergoing processing using an artificial neural network in an inference mode the value for the thickness representing a thickness for each scan of a sensor of the in-situ optical monitoring system to measure the measured spectrum of light, wherein the artificial neural network comprises
a plurality of input nodes, the plurality of input nodes including a multiplicity of input nodes to receive in the inference mode the plurality of component values and one or more input nodes of the plurality of input nodes to receive in the inference mode the one or more values of the one or more processing or environmental variables other than the plurality of component values,
an output node to output the value for the thickness of the outer layer of the substrate for each scan of the sensor of the in-situ optical monitoring system to measure the measured spectrum of light, and
a plurality of hidden nodes connecting the plurality of input nodes to the output node, and

determine at least one of whether to halt processing of the substrate or an adjustment for a processing parameter based on the value for the thickness of the outer layer of the substrate undergoing processing.