The accurate measurement of the thickness profile, particularly in the presence of non-uniform thin films deposited on substrates with warpage, is a crucial aspect of various applications spatially, in the overlay process of the semiconductor industry. The conventional method of Fizeau interferometer-based shape and geometry measurement has limitations in nanometer-level accurate volumetric profile measurement when non-uniform and complex thin films are deposited upon a warped Si substrate. Spectroscopic ellipsometry can be the best candidate for ultra-thin film volumetric thickness profile metrology rather than spectral reflectometry. But current spectral ellipsometry is time consuming. To address these challenges, our research group has made significant advancements in the field of spectroscopic imaging ellipsometry by developing dynamic spectroscopic imaging ellipsometry (DSIE). In this study, we describe a dynamic ultra-thin film thickness line-profile measurement method by adding a Mach-Zehnder interferometer module to a dynamic spectroscopic imaging ellipsometer. The proposed system can provide nanometer-level ultra-thin film thickness line-profile and the warped surface profile information of a Si substrate simultaneously.
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