Importance

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Abstract

Change in a torque waveform is monitored while removing continuously-varied periodic noise in real time, and the change in the torque waveform caused purely by the wafer state is detected by separating noise components while removing the noise not caused by the wafer state such as drift noise caused by dressing conditions and the polishing pad state, thereby reliably detecting a polishing end point with high precision when polishing is finished. A polishing end point detection device utilizing torque change for analyzing periodic components in data by subjecting Fourier transformation to the measured data, and calculating moving average processing time for removing periodic noise components based on the analyzed periodic components, and correcting the waveform by performing averaging process based on the moving average processing time calculated in real time for the data, and detecting the polishing end point of a predetermined film based on a change in the corrected torque waveform.

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First Claim