Rigorous mask modeling using waveguide and FDTD methods. An assessment for typical hyper NA imaging problems

This paper presents an evaluation of the finite-difference time-domain method (FDTD) and of the waveguide method (WG) for the simulation of typical hyper NA imaging problems. In contrast to previous comparisons of rigorous mask modeling methods, which were restricted to the assessment of few near fields, diffraction efficiencies, or aerial images at fixed imaging configurations, we compare the methods in terms of CPU-time and memory requirements, their capability to predict parameter dependencies and more global lithographic process characteristics such as process windows and through-pitch behavior.