  Rigorous computer simulations of propagating electromagnetic fields have
become an important tool for optical metrology and optics design of
nanostructured components. As has been shown in previous benchmarks some of the
presently used methods suffer from low convergence rates and/or low accuracy of
the results and exhibit very long computation times which makes application to
extended 2D layout patterns impractical. We address 3D simulation tasks by
using a finite-element solver which has been shown to be superior to competing
methods by several orders of magnitude in accuracy and computational time for
typical microlithography simulations. We report on the current status of the
solver, incorporating higher order edge elements, adaptive refinement methods,
and fast solution algorithms. Further, we investigate the performance of the
solver in the 3D simulation project of light diffraction off an alternating
phase-shift contact-hole mask.
