Robust source and polarization joint optimization for thick-mask lithography imaging
Date
2024-10-31
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Micro/Nanopatterning, Materials, and Metrology
Abstract
Background
Optical lithography is a key technology to fabricate very large-scale integrated circuits. As the critical dimension of integrated circuits approaches the diffraction resolution limit, thick-mask effects have begun to significantly influence the lithography image quality.
Aim
We develop a computational lithography approach, dubbed source and polarization joint optimization (SPO), to compensate for image distortion in the thick-mask lithography process.
Approaches
SPO manipulates the intensity distribution and polarization angles of the pixelated light source to modulate the diffracted light field off the photomask, thus improving the lithography image quality over the variation of process conditions. The thick-mask effects are accounted for in the imaging model using the rigorous three-dimensional diffraction simulator. The SPO framework is established to consider the image errors on both focal and defocus imaging planes with exposure variation. Two kinds of gradient-based optimization algorithms, namely, simultaneous SPO (SiSPO) and sequential SPO (SeSPO), are developed.
Result
The superiority of the proposed methods is verified by a set of numerical experiments.
Conclusion
The SeSPO algorithm outperforms the SiSPO algorithm in terms of image fidelity, process window, and computational efficiency.
Description
This article was originally published in Journal of Micro/Nanopatterning, Materials, and Metrology. The version of record is available at: https://doi.org/10.1117/1.JMM.23.4.043201.
© 2024 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.
Keywords
computational lithography, optical lithography, source and polarization joint optimization, thick-mask effect, inverse problem
Citation
Shengen Zhang, Xu Ma, and Gonzalo R. Arce "Robust source and polarization joint optimization for thick-mask lithography imaging," Journal of Micro/Nanopatterning, Materials, and Metrology 23(4), 043201 (31 October 2024). https://doi.org/10.1117/1.JMM.23.4.043201