Model-based optical scatterometry is a widely utilized non-destructive measuring technique in semiconductor manufacturing for retrieving features on wafers. It offers an attractive solution for quality control and process monitoring. However, the increasing complexity of 3D nanoscale device structures presents significant challenges for optical scatterometry. To address these challenges, it is crucial to integrate different methods and create a hybrid metrology approach that could encompass measurements, modeling, and data analysis techniques. To tackle this objective, we explore in this study two alternative approaches for parameter reconstruction, distinct from the conventional library search method. The first approach utilizes a neural network based on a Resnet architecture, while the second approach employs the Levenberg-Marquardt algorithm, a nonlinear least square fitting technique. By performing a comparative analysis of the two methods, we propose a strategy to combine them for accurate and efficient parameter reconstructions.
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