Peak-based endpointing for chemical mechanical polishing
AssigneeApplied Materials, Inc.
InventorsDominic J. Benvegnu, Boguslaw A. Swedek, David J. Lischka
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Abstract
A method of polishing includes storing a predetermined location and a predetermined number as criteria for detecting an end point, polishing a substrate, measuring a sequence of current spectra of light reflected from the substrate while the substrate is being polished, identifying a plurality of peaks or valleys that persist with an evolving location through at least some of the sequence of current spectra, counting a number of peaks or valleys that were identified that pass the predetermined location as polishing progresses, and ceasing to polish the substrate when the number counted reaches the predetermined number.
Claims12
A method comprising:
- storing a predetermined location and a predetermined number as criteria for detecting an end point;
- polishing a substrate;
- measuring a sequence of current spectra of light reflected from the substrate while the substrate is being polished;
- identifying a plurality of peaks or valleys in the sequence of current spectra, wherein the peaks or valleys persist with an evolving location through at least some of the sequence of current spectra;
- counting a number of peaks or valleys that were identified that pass the predetermined location as polishing progresses;
- and
- ceasing to polish the substrate when the number counted reaches the predetermined number.
Dependencies are inferred from the claim text.