16 October 2024 Study of mask error enhancement factor improvement with low-n absorber extreme ultraviolet lithography mask
Author Affiliations +
Abstract

In the case of low-k1 imaging, critical dimension (CD) variation on extreme ultraviolet (EUV) mask enhances on wafer, which is called mask error enhancement factor (MEEF). CD variation for tighter line and space (L/S) features on the photomask has taken up a large fraction of wafer CD variation. Understanding the mask contribution to EUV lithography (EUVL) is one of the important initiatives to further optimize 0.33-NA EUVL employability. The optical properties of the EUV mask absorber have the potential to improve Normalized Image Log-Slope (NILS). Low-n attenuated phase-shift mask (attPSM) is expected to mitigate mask three-dimensional effects and to enhance the image contrast compared with a traditional Ta-based mask. We experimentally evaluated the MEEF on the drawn feature size, illumination, and mask absorber properties to characterize the impact of optical factors on MEEF using the NXE:3400B EUV scanner. This paper covers two types of mask absorber materials which are Ta-based and low-n attPSM. We experimentally demonstrated that a low-n mask is expected to improve the balance of MEEF at vertical L/S through pitch due to suppression of best focus variation. We also tried to identify the suitable absorber optical properties in terms of MEEF and NILS on both 0.33/0.55-NA EUVL through lithographic simulations.

© 2024 Society of Photo-Optical Instrumentation Engineers (SPIE)
Yosuke Takahata, Tatiana Kovalevich, Danilo De Simone, Yusuke Tanaka, and Vicky Philipsen "Study of mask error enhancement factor improvement with low-n absorber extreme ultraviolet lithography mask," Journal of Micro/Nanopatterning, Materials, and Metrology 23(4), 044401 (16 October 2024). https://doi.org/10.1117/1.JMM.23.4.044401
Received: 31 May 2024; Accepted: 11 September 2024; Published: 16 October 2024
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Extreme ultraviolet lithography

Extreme ultraviolet

Optical properties

Nanoimprint lithography

Light sources and illumination

3D mask effects

Critical dimension metrology

RELATED CONTENT

Study of MEEF improvement with low-n absorber EUVL mask
Proceedings of SPIE (April 10 2024)
EUVL mask performance and optimization
Proceedings of SPIE (April 16 2012)

Back to Top