Imaging ellipsometry for high-spatial-resolution metrology

The polarization change that accompanies diffraction from sub-wavelength features is used as a sensitive measure of the feature shape. This sub-wavelength measurement capability is explored by comparing vector-based diffraction models with experimentally obtained data from a novel imaging ellipsometer. This imaging ellipsometer is able to measure samples with high spatial resolution in a parallel fashion by using a high-numerical-aperture lens. Two-dimensional surface maps can be generated without scanning. Our novel metrology tool could provide a solution to the imminent metrology challenges in semiconductor industry.