Application of a bandwidth correction method to thin-film reflectance measurements

Abstract Accurate measurement of thin-film layer thicknesses is needed in both scientific and industrial applications. Proper bandwidth correction of the spectral data, obtained with monochromator and array spectrometers, can improve measurement accuracy of reflectometry, particularly for coated samples with sharp spectral features. This study investigates the Richardson–Lucy method for bandwidth correction in reflectometry using a 2 μm-thick SiO 2 layer on Si sample as an example. The reflectance spectrum, with multiple oscillations in the 300 nm–950 nm wavelength range, was analysed using a MATLAB-based transfer-matrix software for reflectance calculation. Experimental results showed that using bandwidth-corrected data improved the reliability of the SiO 2 layer thickness characterization, specifically estimation of the width of thickness distribution. Sensitivity analysis and uncertainty evaluation further validated the method’s efficiency, indicating good model sensitivity. The Richardson–Lucy bandwidth correction method was confirmed as a reliable tool for improving the accuracy of thin-film measurements using the reflectometry technique.