Thin-Film Characterization via Referenced Spectroscopic Ellipsometry Enpowered by Weak Measurement

Quantitative characterization of thin films is critically important across diverse fields. In this study, a novel technique called referenced spectroscopic ellipsometry enpowered by weak measurement (RSEWM) is introduced for high-precision detection of minute variations of thin film parameters, which leverages the amplified sensitivity of weak measurement to polarization shift of reflected light. Numerical simulation and experimental validation confirm that the spectra obtained by RSEWM exhibit exceptional sensitivity to deviations in thin film parameters from a reference standard. By solving the inverse problem through iterative spectrum fitting, thin film parameters can be retrieved with sub-nanometer resolution. Given its high efficiency, we anticipate RSEWM will emerge as a powerful tool for nanoscale metrology, with broad applications spanning semiconductor manufacturing to materials science.