Polishing state monitoring method and polishing state monitoring device of the wafer

摘要

PROBLEM TO BE SOLVED: To improve the control precision at a polishing end point by excluding an influence of disturbance to precisely detect a polished state of a wafer in CMP.;SOLUTION: A device for monitoring a polished state includes a means which irradiates a surface of a wafer W by white light and separates the reflected light into spectral components, and includes a step of performing Fourier transform of a reflectance profile for a wavelength or a wave number reflected from the surface of the wafer W during polishing; a step of refining a changing periodical portion of the waveform subjected to the Fourier transform; and a step of restoring the reflectance profile by inverse Fourier transform of the waveform after filtering. A prescribed reflectance profile obtained at the polishing end point and a reflectance profile during polishing have top and bottom positions collated with each other in a prescribed region, and the end point of polishing is detected on the basis of collation results, whereby the influence of disturbance occurring due to slurries and the like is reduced.;COPYRIGHT: (C)2010,JPO&INPIT