Modeling of radiative properties of Sn plasmas for extreme-ultraviolet source

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3373427· OSTI ID:21476278

Sasaki, Akira ^[1]; Sunahara, Atsushi; Furukawa, Hiroyuki ^[2]; Nishihara, Katsunobu; Fujioka, Shinsuke ^[3]; Nishikawa, Takeshi ^[4]; Koike, Fumihiro ^[5]; Ohashi, Hayato; Tanuma, Hajime ^[6]

---

1. Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1 Umemidai, Kizugawa-shi, Kyoto 619-0215 (Japan)
2. Institute for Laser Technology, 1-8-4 Utsubohonmachi, Nishi-ku, Osaka 550-0004 (Japan)
3. Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan)
4. Department of Electrical and Electronic Engineering, Okayama University, 1-1 Naka 1-chome, Tsushima, Okayama 700-8530 (Japan)
5. Physics Laboratory, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 (Japan)
6. Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan)

Atomic processes in Sn plasmas are investigated for application to extreme-ultraviolet (EUV) light sources used in microlithography. We develop a full collisional radiative (CR) model of Sn plasmas based on calculated atomic data using Hebrew University Lawrence Livermore Atomic Code (HULLAC). Resonance and satellite lines from singly and multiply excited states of Sn ions, which contribute significantly to the EUV emission, are identified and included in the model through a systematic investigation of their effect on the emission spectra. The wavelengths of the 4d-4f+4p-4d transitions of Sn{sup 5+} to Sn{sup 13+} are investigated, because of their importance for determining the conversion efficiency of the EUV source, in conjunction with the effect of configuration interaction in the calculation of atomic structure. Calculated emission spectra are compared with those of charge exchange spectroscopy and of laser produced plasma EUV sources. The comparison is also carried out for the opacity of a radiatively heated Sn sample. A reasonable agreement is obtained between calculated and experimental EUV emission spectra observed under the typical condition of EUV sources with the ion density and ionization temperature of the plasma around 10{sup 18} cm{sup -3} and 20 eV, respectively, by applying a wavelength correction to the resonance and satellite lines. Finally, the spectral emissivity and opacity of Sn plasmas are calculated as a function of electron temperature and ion density. The results are useful for radiation hydrodynamics simulations for the optimization of EUV sources.

• OSTI ID: 21476278
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 11; Other Information: DOI: 10.1063/1.3373427; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
74 ATOMIC AND MOLECULAR PHYSICS
CHARGE EXCHANGE
COMPARATIVE EVALUATIONS
CONFIGURATION INTERACTION
ELECTRON TEMPERATURE
EMISSION SPECTRA
EMISSIVITY
EXCITED STATES
EXTREME ULTRAVIOLET RADIATION
HYDRODYNAMICS
ION DENSITY
ION TEMPERATURE
IONIZATION
LASER-PRODUCED PLASMA
LIGHT SOURCES
OPACITY
PLASMA DENSITY
PLASMA SIMULATION
TIN
TIN IONS
CHARGED PARTICLES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
EVALUATION
FLUID MECHANICS
IONS
MECHANICS
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA
RADIATION SOURCES
RADIATIONS
SIMULATION
SPECTRA
SURFACE PROPERTIES
ULTRAVIOLET RADIATION