EUV and debris characteristics of a laser-produced tin plasma using a colloidal tin dioxide jet target

We investigated the effective technique for debris suppression of a laser-produced tin plasma using a colloidal tin dioxide jet target, as well as the EUV emission and debris characteristics of the target. By using double pulse laser irradiation with an optimum delay of 100 ns, the EUV conversion efficiency of 1.2% at 13.5 nm was observed. The peak energy and intensity of ionic debris were simultaneously reduced by the double laser pulse irradiation. The peak kinetic energy of the singly-ionized tin ion was reduced from 9 to 3 keV, when an expanding low-density preplasma was produced. The dominant debris from a laser-produced tin plasma, which was deposited on a witness plate, was found to be oxidized tin (SnO_x). By heating a witness plate at 100 °C, the deposited debris amount decreased to approximately one third.