US 12,759,107 B2Granted

Generation of background signal sequence using an in-situ monitoring system in chemical mechanical polishing

AssigneeApplied Materials, Inc.

InventorsKun Xu, Jimin Zhang, Chen-Wei Chang, Haosheng Wu, Patrick A. Higashi, Jianshe Tang

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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.

Claims20

Dependent claims

A method of generating a sequence of reference traces for use in in-situ monitoring, the method comprising:

measuring an angular orientation of a calibration substrate;
rotating a carrier head holding the calibration substrate to a first predetermined angular position based on the measured angular orientation;
rotating a platen to a second predetermined angular position;
bringing the calibration substrate into contact with a polishing pad on the platen with calibration substrate at the first predetermined angular position and the platen at the second predetermined angular position;
rotating the platen and the carrier head with the calibration substrate in contact with the polishing pad;
monitoring the calibration substrate 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 wherein each reference trace includes a series of signal values;
and
storing the sequence of reference traces and labelling each reference trace to distinguish an order of the reference traces within the sequence.

5 more elements

A computer program product computer program product residing on a non-transitory computer readable medium and comprising instructions for causing one or more computers to:

receive a measurement of an angular orientation of a calibration substrate;
cause a carrier head holding the calibration substrate to rotate to a first predetermined angular position based on the measured angular orientation;
cause a platen to rotate a second predetermined angular position;
cause the calibration substrate to be brought into contact with a polishing pad on the platen with calibration substrate at the first predetermined angular position and the platen at the second predetermined angular position;
cause the platen and the carrier head to rotate with the calibration substrate in contact with the polishing pad;
receive a sequence of reference traces from an in-situ monitoring system with each respective reference trace of the sequence of reference traces corresponding to a respective sweep of a sequence of sweeps by a sensor of the in-situ monitoring system across the calibration substrate, and wherein each reference trace includes a series of signal values;
and
store the sequence of reference traces and labelling each reference trace to distinguish an order of the reference traces within the sequence.

5 more elements

Dependencies are inferred from the claim text.