Tin laser-produced plasma source modeling at 13.5nm for extreme ultraviolet lithography

Abstract

Extreme ultraviolet lithography semiconductor manufacturing requires a 13.5nm light source. Laser-produced plasma emission from Sn V–Sn XIV ions is one proposed industry solution. The effect of laser pulse width and spatial profile on conversion efficiency is analyzed over a range of power densities using a two-dimensional radiative magnetohydrodynamic code and compared to experiment using a 1.064μm, neodymium:yttrium aluminium garnet laser on a planar tin target. The calculated and experimental conversion efficiencies and the effects of self-absorption in the plasma edge are compared. Best agreement between theory and experiment is found for an 8.0ns Gaussian pulse.