Journal article

Publication year: 2007

Pages: 1123-1138

Journal: Journal of vacuum science & technology B

Volume number: 25

Issue number: 4

ISSN: 1071-1023

DOI Link: https://doi.org/10.1116/1.2743648

Publisher: Society by the American Institute of Physics

Abstract: 

Extreme ultraviolet lithography (EUVL) is a leading candidate for next-generation lithography for the semiconductor industry. This technology uses EUV light with a wavelength of 13.5nm" role="presentation">13.5nm (92.5eV)" role="presentation">(92.5eV) to be able to produce features as small as 20nm" role="presentation">20nm in size. The short wavelength of EUV means that reflective optics is needed for lithography in the form of Si–Mo multilayer stacks. However, surface contamination by water and hydrocarbons together with EUV light reduces unacceptably the mirror reflectivity with time. In this article, the authors review the material properties of two promising capping layer materials, Ru and RuO2" role="presentation">RuO2, for protecting the EUVL mirrors against oxidation, carbon uptake, and the permeation of hydrogen and oxygen. Special emphasis is put on the surface properties of these potential cap layer systems. For both materials the microstructure, the morphology, and the stability under oxidizing and reducing environments are reviewed to promote the search for a successful candidate for a capping layer material of EUV optics.

Harvard Citation style: Over, H., He, Y., Farkas, A., Mellau, G., Korte, C., Knapp, M., et al. (2007) Long-term stability of Ru-based protection layers in extreme ultraviolet lithography: A surface science approach, Journal of vacuum science & technology B, 25(4), pp. 1123-1138. https://doi.org/10.1116/1.2743648

APA Citation style: Over, H., He, Y., Farkas, A., Mellau, G., Korte, C., Knapp, M., Chandhok, M., & Fang, M. (2007). Long-term stability of Ru-based protection layers in extreme ultraviolet lithography: A surface science approach. Journal of vacuum science & technology B. 25(4), 1123-1138. https://doi.org/10.1116/1.2743648