Influence of configuration interaction on satellite lines of xenon and tin in the EUV region

Theoretical line strengths and positions of satellite lines of xenon and tin ions are computed in the EUV region (transitions from doubly excited configurations or between singly excited configurations). Calculations are conducted with HULLAC parametric multi-configuration relativistic code. Influence of configuration interaction is investigated for doubly excited configurations of ions from Pd- to Rb-like. The emission close to 13.5 nm, which is of interest to the EUV lithography, is detailed. A strong narrowing of 4d–4f/4d–4p group of satellite lines is observed, compared to the calculation without configuration interaction. The emissivity is strongly enhanced in the centre of this group of lines. This strongly increases the EUV emission at 13.5 nm for tin at moderate to high densities. The EUV emission of xenon at 13.5 nm is enhanced by 4d–5p satellite lines of Xe 9+ and 10+. Radiative transitions between singly excited configurations and between doubly excited configurations also enhance the emission at 13.5 nm, especially 6g–4f transitions of Xe 9+, 10+ and 5g–4f transitions of Xe 11+.