Scattered light simulation of periodic Nano-structures: verification and comparative analysis

Periodic nano-structures find application in optics, material science and engineering. These periodic structures are often in the sub-100 nm range, i.e., below the optical resolution limit. Scattered light measurements that are sufficiently fast are suitable for in-process inspection. However, the relationship between the measured scattered light and the state of the nano-structure (defect-free / defective) is generally unknown. In order to determine this relationship, optical experiments are to be carried out virtually, i.e. numerically (scattered light simulations). The main task of this project is to verify the simulation results by doing a comparative study between two different simulation approaches – Discrete Dipole Approximation (DDA) / Rigorous Coupled Wave Analysis (RCWA). In addition, the simulation results will be compared with the analytical knowledge from scalar diffraction theory. This will test the simulation quality and determine the more appropriate option for future study with nano-structure defects.