• DOI:10.1088/0022-3727/39/3/010
• Corpus ID: 34621555

Spectral control of emissions from tin doped targets for extreme ultraviolet lithography

@article{Harilal2006SpectralCO,
  title={Spectral control of emissions from tin doped targets for extreme ultraviolet lithography},
  author={S. S. Harilal and B. O’Shay and Mark S. Tillack and Yezheng Tao and R. R. Paguio and Abbas Nikroo and Christina A. Back},
  journal={Journal of Physics D: Applied Physics},
  year={2006},
  volume={39},
  pages={484 - 487}
}

• S. S. Harilal, B. O’Shay, +4 authors C. Back
• Published 7 February 2006
• Physics
• Journal of Physics D: Applied Physics

We have investigated the unresolved transition array (UTA) emission around 13.5 nm from solid density tin and tin doped foam targets. Extreme ultraviolet (EUV) spectral measurements were made in the wavelength region 11–17 nm using a transmission grating spectrograph and the EUV in-band conversion efficiency was measured using an absolutely calibrated EUV calorimeter. The aim of this work was to optimize the UTA emission with the proper density of tin dopant in low-Z foam targets. The addition of tin as an impurity leads to a reduction in the plasma continuum and narrowing of the UTA compared with fully dense tin targets. Our studies indicate that the required percentage of tin for obtaining bright in-band spectral emission is less than 1%.