Substrate polishing metrology using interference signals
AssigneeApplied Materials, Inc.
InventorsManoocher Birang, Grigory Pyatigorsky
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Abstract
A method of polishing a substrate includes holding the substrate on a polishing pad with a polishing head, wherein the polishing pad is supported by a platen, creating relative motion between the substrate and the polishing pad to polish a side of the substrate, generating a light beam and directing the light beam towards the substrate to cause the light beam to impinge on the side of the substrate being polished. Light reflected from the substrate is at a detector to generate an interference signal. A measure of uniformity is computed from the interference signal.
Claims10
A method of polishing a substrate, comprising:
- holding the substrate on a polishing pad with a polishing head, wherein the polishing pad is supported by a platen;
- creating relative motion between the substrate and the polishing pad to polish a side of the substrate;
- generating a light beam;
- directing the light beam towards the substrate to cause the light beam to impinge on the side of the substrate being polished;
- receiving light reflected from the substrate at a detector to generate a time-varying interference signal;
- and
- computing a measure of uniformity from the interference signal based on a difference between the time-varying interference signal and a time-varying base signal.
A method of polishing a substrate, comprising:
- holding the substrate on a polishing pad with a polishing head, wherein the polishing pad is supported by a platen;
- creating relative motion between the substrate and the polishing pad to polish a side of the substrate;
- generating a light beam;
- directing the light beam towards the substrate to cause the light beam to impinge on the side of the substrate being polished;
- receiving light reflected from the substrate at a detector to generate an interference signal;
- and
- displaying a characterizing waveform for an operator to see, the characterizing waveform presenting data for a period of time that extends over multiple cycles of the interference signal.
Dependencies are inferred from the claim text.