Translator Disclaimer
Paper
26 May 2022 Characterizing EMA modelled EUV absorbers for high reflectivity: high phase performance
Author Affiliations +
Abstract
Attenuated phase shifting masks (attPSM) for EUV lithography have shown the potential to improve the aerial image contrast through light and phase modulation and reduced mask three-dimensional (M3D) effects through thinner absorber. However, a robust optical design capable of generating almost identical performance for various patterns and feature sizes needs to be determined. The ability to identify and experimentally verify various mask absorber candidates is both challenging and expensive. Effective media approximation (EMA) identified material candidates have been shown to simplify the determination of material candidates through known optical constants of the constituent elements. An approach to engineer the desired optical properties and experimentally verify EMA modeling technique through multilayer thin films is presented. Mo – Ni multilayer films satisfying EMA requirement are deposited through RF magnetron sputtering. The verification of optical constants for multilayer films with 20%, 50% and 90% Ni volume fractions is performed at visible wavelengths through UV-Vis-NearIR variable angle spectroscopic ellipsometry (VASE). EMA modeled multilayer absorber candidates are shown to have the flexibility in obtaining desired optical properties based on the layout-design requirements.
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Rajiv N. Sejpal and Bruce W. Smith "Characterizing EMA modelled EUV absorbers for high reflectivity: high phase performance", Proc. SPIE 12051, Optical and EUV Nanolithography XXXV, 120510E (26 May 2022); https://doi.org/10.1117/12.2617589
PROCEEDINGS
9 PAGES


SHARE
Advertisement
Advertisement
KEYWORDS
Reflectivity

Nickel

Photomasks

Dielectrics

Extreme ultraviolet lithography

Molybdenum

Refractive index

RELATED CONTENT


Back to Top