In-process optical characterization method for sub-100-nm nanostructures

Optical measurements based on laser light scattering by nanostructures provide fast and contactless measurement of the surface of nanostructures for defects. In this paper, a novel in-process measurement method based on coherent laser light scattering by sub-100-nm structures is presented. It is shown that nanostructure defects can be identified by their unique scattering pattern. This is investigated by using modified algorithms of the discrete dipole approximation (DDA). Also hardware acceleration of the DDA algorithm on a General Purpose Graphical Processing Unit (GPGPU) platform shows a speedup of a factor of 5 over a high end CPU based platform.