The modeling of EUV sources by considering detailed kinetics, including in-line in the gasdynamics calculation

The model of nonstationary nonequilibrium radiating plasma is developed by considering level kinetics and radiation transport in spectral lines self-consistently. A spherical target explosion and radiation caused by a laser pulse is simulated. The two-temperature 1D Lagrange gasdynamic equation is solved numerically. The radiation field and the level kinetics are considered self-consistently by two different approaches: by using interpolation between the precalculated tables of spectral parameters and by accounting for the detailed level kinetics included in-line in the gasdynamic calculations. Conversion efficiency of EUV radiation is estimated for lithium and tin plasma. It is important for EUV lithography used for microchip production. The conversion efficiency under the optimal parameters of laser pulse is as follows: for lithium it is 1%, and for tin, it is 5%, and it is in a good agreement with the experimental data.