Film thickness measurement can be realized using white light interferometry,but it is challenging to guarantee high precision in a large range of thicknesses.Based on scanning white light interferometry,we propose a s...Film thickness measurement can be realized using white light interferometry,but it is challenging to guarantee high precision in a large range of thicknesses.Based on scanning white light interferometry,we propose a spectral-temporal demodulation scheme for large-range thickness measurement.The demodulation process remains unchanged for either coatings or substrate-free films,while some adjustments are made according to the estimated optical thickness.Experiments show that the single-point repeatabilities for 500 nm SiO_(2) coating and 68μm substrate-free Si film are no more than 0.70 nm and 1.22 nm,respectively.This method can be further developed for simultaneous measurement of surface profile and film thickness.展开更多
基金supported by the National Natural Science Foundation of China(Nos.62005062 and 61975040)the National Science Fund for Distinguished Young Scholars of China(No.61925501)the Open Fund of Guangdong Provincial Key Laboratory of Information Photonics Technology(No.GKPT20-02)。
文摘Film thickness measurement can be realized using white light interferometry,but it is challenging to guarantee high precision in a large range of thicknesses.Based on scanning white light interferometry,we propose a spectral-temporal demodulation scheme for large-range thickness measurement.The demodulation process remains unchanged for either coatings or substrate-free films,while some adjustments are made according to the estimated optical thickness.Experiments show that the single-point repeatabilities for 500 nm SiO_(2) coating and 68μm substrate-free Si film are no more than 0.70 nm and 1.22 nm,respectively.This method can be further developed for simultaneous measurement of surface profile and film thickness.
