Consequences of Plasmonic Effects in Photomasks

In the implementation of most resolution enhancement techniques (RET) for optical lithography, full 3-D simulation of the wave propagation and scattering through the mask apertures must be computed for situations when 'scalar' approximations no longer hold. Using commercial 3-D electromagnetic solvers such as the program TEMPEST, some topography effects due to scattering, such as the intensity imbalance observed in phase masks, can be accurately predicted.