| 摘要 |
<p>A method of controlling a polishing operation includes polishing a substrate, during polishing obtaining a sequence over time of measured spectra from the substrate with an in-situ optical monitoring system, for each measured spectrum from the sequence of measured spectra applying a Fourier transform to the measured spectrum to generate a transformed spectrum thus generating a sequence of transformed spectra, for each transformed spectrum identifying a peak of interest from a plurality of peaks in the transformed spectrum, for each transformed spectrum determining a position value for the peak of interest in the transformed spectrum thus generating a sequence of position values, and determining at least one of a polishing endpoint or an adjustment of a pressure to the substrate from the sequence of position values.</p> |
