A refractive index calibration method and a wafer polishing endpoint detection method for wafer polishing endpoint detection.

Abstract

This invention discloses a refractive index calibration method for wafer polishing endpoint detection, comprising the following steps: S1, establishing a dispersion model and fitting the refractive index using the dispersion model and corresponding model parameters; S2, determining one or more initial values ​​for the dispersion model parameters; S3, calibrating based on the initial values ​​and gradient information to obtain the final model parameters; S4, generating the refractive index using the calibrated parameters for thickness calculation and performing polishing endpoint detection. This invention also discloses a wafer polishing endpoint detection method. This invention adds refractive index calibration, eliminating the need for other complex methods and destructive contact with the wafer. It uses the refractive index of the wafer layer to be polished as a parameter and calibrates it using an algorithm, making it more consistent with the relationship between the currently measured wafer reflection spectrum information and the actual thickness, improving the accuracy and consistency of thickness calculation, thereby improving the accuracy of polishing endpoint detection.

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