Paper
1 July 2002 Simulation studies of roughness-smoothing effect of molybdenum/silicon multilayer coating based on resputtering model
Taro Ogawa, Masaaki Ito, Hiromasa Yamanashi, Hiromasa Hoko, Eiichi Hoshino, Shinji Okazaki
Author Affiliations +
Abstract
For an extreme UV lithography (EUVL) mask, one cause of phase defects is bumps and divots on the surface that are a few nanometers high. Though phase defects are believed to originate in the roughness of the underlying substrate, recent reports suggest that a molybdenum/silicon (Mo/Si) multilayer deposited by ion beam sputtering smooths out the roughness of the underlying substrate and thus relaxes the specifications for the surface roughness of glass substrates for EUVL masks. In this study, we analyzed this smoothing effect mainly through simulation studies. Our simulation is based on the string model and consists of two parts: the deposition of Mo and Si bilayers, and the resputtering of Mo and Si atoms form each layer. The simulation result based on ly on the deposition part suggest that a Mo/Si multilayer conformally coats the bumps and divots of the underlying substrate. These results are in good agreement with transmission electron microscope observations of Mo/Si multilayers deposited onto bumps and divots by magnetron sputtering. When resputtering is added to the simulation, both bumps and divots on the underlying substrate are smoothed out under the same conditions. These result suggest that resputtering is partially responsible for the roughness-smoothing effect that appears during the deposition of a Mo/Si multilayer.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Taro Ogawa, Masaaki Ito, Hiromasa Yamanashi, Hiromasa Hoko, Eiichi Hoshino, and Shinji Okazaki "Simulation studies of roughness-smoothing effect of molybdenum/silicon multilayer coating based on resputtering model", Proc. SPIE 4688, Emerging Lithographic Technologies VI, (1 July 2002); https://doi.org/10.1117/12.472346
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Cited by 4 scholarly publications.
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KEYWORDS
Molybdenum

Multilayers

Silicon

Chemical species

Sputter deposition

Extreme ultraviolet lithography

Coating

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