The Characterization of Gratings Using the Optical Scatterometer

A technique for characterizing gratings, the optical scatterometry, is presented under its both aspects: experimental and theoretical, the way we practice it at the National Institute for Laser, Plasma and Radiation Physics (NILPRP). We present the simple and versatile, precise and capable of complex types of ellipsometric measurements scatterometer that we built at NILPRP together with an example of application for estimating the parameters of a grating. All the prominent features of a scatterometric application are touched: the mechanical and optical design of the measuring device, the remote operating software, the diffraction theory for interpreting the data and the error and sensitivity analysis with stress on the original contributions of the authors.