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

TL;DR

This paper reviews recent advances in simulating electromagnetic light propagation in non-periodic mask patterns, focusing on isolated structures within layered media and methods to efficiently compute far-field information for mask design.

Contribution

It introduces new techniques for rigorous simulation of non-periodic, layered structures, improving accuracy and computational efficiency over traditional periodic assumptions.

Findings

Enhanced simulation accuracy for isolated structures

Efficient extraction of far-field data in non-periodic settings

Applicable to complex layered media with inhomogeneities

Abstract

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.