Investigation of the minimum measurement field of view for imaging ellipsometry by using FDTD method

The high spatial resolution of imaging ellipsometry makes it a highly promising non-contact and non-destructive technique for characterizing thin films, particularly those with non-uniform distributions or well-defined patterns. As the spatial resolution of the imaging system increases, more detailed information about the lateral distribution of the sample surface can be obtained. In this study, based on high-spatial-resolution ellipsometry measurements and the geometric multiple reflections of light within thin films, we investigated the minimum measurement field of view using finite-difference time-domain simulations for the air/thin film/substrate structure in terms of the wavelength and the angle of incidence. The criterion of measurement field of view can provide guidelines for the performance of high-resolution imaging ellipsometry in evaluating thin-film distributions.