Finite Element Simulation of Light Propagation in Non-Periodic Mask Patterns

Rigorous electromagnetic field simulations are an essential part for scatterometry and mask pattern design. Today mainly periodic structures are considered in simulations. Non-periodic structures are typically modeled by large, artificially periodified computational domains. For systems with a large radius of influence this leads to very large computational domains to keep the error sufficiently small. In this paper we review recent advances in the rigorous simulation of isolated structures embedded into a surrounding media. We especially address the situation of a layered surrounding media (mask or wafer) with additional infinite inhomogeneities such as resist lines. Further we detail how to extract the far field information needed for the aerial image computation in the non-periodic setting.