Imaging Mueller matrix ellipsometry for the characterisation of nanoscale structures

In semiconductor industry, the production and associated quality control of nanoscale structures is of great importance. An important factor in the dimensional characterisation of such small structures is the polarisation information, which is why ellipsometry is a very suitable measurement method for that purpose. Imaging ellipsometry can be used for pixel-wise evaluation, which enables more localized measurements than conventional ellipsometry. We have measured different structures, isolated lines of different size as well as circle grating in small target fields to investigate the measurement capabilities and physical limits of this measurement method. Numerical simulations based on the finite element method are used to solve the inverse problem and to determine the structural parameters. We compare the simulations and the measurement and present the results for the derived structure parameters.