CPC H01L 22/26 (2013.01) [B24B 37/013 (2013.01); B24B 37/205 (2013.01); B24B 49/08 (2013.01); B24B 49/12 (2013.01); B24D 7/14 (2013.01); H01L 21/30625 (2013.01); H01L 21/31053 (2013.01); H01L 21/31055 (2013.01); H01L 21/3212 (2013.01); H01L 21/67075 (2013.01); H01L 21/67092 (2013.01); H01L 21/67253 (2013.01)] | 11 Claims |
1. A method of controlling a chemical mechanical polishing operation, comprising:
storing a plurality of library spectra, each library spectrum of the plurality of library spectra having a stored associated value representing a degree of progress through a polishing process;
polishing a substrate;
measuring a sequence of spectra from the substrate in-situ during polishing;
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;
for each best matching library spectrum from the sequence of best matching library spectra, determining the stored associated value for the best matching library spectrum to generate a sequence of values representing a progression of polishing of the substrate;
comparing the sequence of values to a target value; and
triggering a polishing endpoint when the sequence of values reaches the target value.
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