Discrete Sources Method for light scattering analysis of non-axisymmetric features of a substrate

The Discrete Sources Method (DSM) has been extended to analyze polarized light scattering by non-axial symmetric nano-sized features on a plane substrate. A detailed description of the corresponding numerical scheme is provided. Using a “fictitious” particle approach the new DSM model enables to consider scattering from such substrate defects as a line bump and a line pit. The developed computer model has been employed for demonstrating the ability to perform a comparative analysis of light scattering from such line features. Simulation results corresponding to the Differential Scattering Cross-Section (DSC) and the integral response for P/S polarized light are presented. It was found that the integral response can change by an order of magnitude depending on the orientation of the linear defect with respect to the direction of the incident laser light. In addition, it was shown that some defects can turn out to be “invisible” if an oblique angle of incidence is chosen.