Large-Area Scatterometry for Nanoscale Metrology

Many applications across photonics and semiconductor industries require the fabrication of nanostructures with non-trivial geometries with a precision and reproducibility down to the nanometer scale. Slanted gratings and metamaterials are examples of such designs that have vast applications in Augmented Reality and LiDAR. State-of-the-art lithography techniques, such as nanoimprint lithography or UV lithography, can provide such levels of fabrication precision for high-volume production. However, a rapid in-line quality inspection method for such complex patterns is required to monitor the fabrication process, verify the sample quality, and to ensure reproducibility. Here, we demonstrate a novel technique that allows us to inspect the quality of the samples in a non-destructive and fast manner, and to extract geometrical parameters of the nanostructures over large areas, generating spatial variations maps across wafers.