Patent ID: 8687197
Filing Date: 2014-04-01
Classification: B24B,G01N,H01L

Abstract:
1. A method of monitoring progress of polishing of a substrate having on a surface thereof at least two regions including a first region and a second region with different structures, said method comprising: polishing the substrate by pressing the substrate against a polishing pad on a rotating polishing table; during said polishing of the substrate, applying light to plural measurement points on the substrate; receiving reflected light from each measurement point; measuring intensity of the reflected light throughout a predetermined wavelength range; producing a spectrum of the reflected light from measurement values of the intensity; classifying the spectrum as spectrum of the reflected light from the first region or as spectrum of the reflected light from the second region based on a shape of the spectrum or the intensity of the reflected light; and monitoring the progress of polishing of the substrate based on a temporal change in the spectrum of the reflected light from the first region, wherein said classifying of the spectrum comprises: classifying the spectrum as a spectrum of the reflected light from the first region when the number of local maximum points and/or local minimum points that appear on the spectrum agrees with a predetermined reference number; and classifying the spectrum as a spectrum of the reflected light from the second region when the number of local maximum points and/or local minimum points that appear on the spectrum does not agree with the predetermined reference number.