Energetic and Thermal Sn Interactions and Their Effect on EUVL Source Collector Mirror Lifetime at High Temperatures

Published

October 1, 2007

Author(s)

J P. Allain, M Nieto, M R. Hendricks, A Hassanein, Charles Tarrio, Steven Grantham, Vivek Bakshi

Abstract

Exposure of collector mirrors facing the hot, dense pinch plasma in plasma-based EUV light sources remains one of the highest critical issues of source component lifetime and commercial feasibility of EUV lithography technology. Studies at Argonne have focused on understanding the underlying mechanisms that hinder collector mirror performance under Sn exposure and developing methods to mitigate them. Both Sn ion irradiation and thermal evaporation exposes candidate mirrors tested (i.e., Ru, Rh and Pd) in the experimental facility known as IMPACT (Interaction of Materials with charged Particles and Components Testing). Studies have led to an understanding of how Sn energetic ions compared to Sn thermal atoms affect three main surface properties of the collector mirror: 1) surface chemical state, 2) surface structure and 3) surface morphology. All these properties are crucial in understanding how collector mirrors will respond to Sn-based EUV source operation. This is primarily due to the correlation of how variation in these properties affects the reflectivity of photons in the EUV spectral range of interest (in-band 13.5-nm). This paper discusses the first property and its impact on 13.5-nm reflectivity.

Citation

SPIE

Volume

6517

Pub Type

Journals

Keywords

EUV collector optics, EUV reflectivity, ion scattering spectroscopy, Sn deposition, Sn implantation, threshold sputtering

Citation

Allain, J. , Nieto, M. , Hendricks, M. , Hassanein, A. , Tarrio, C. , Grantham, S. and Bakshi, V. (2007), Energetic and Thermal Sn Interactions and Their Effect on EUVL Source Collector Mirror Lifetime at High Temperatures, SPIE (Accessed October 14, 2025)