Debris mitigation in a laser-produced tin plume using a magnetic field

Debris mitigation in a laser-produced tin plume is one of the most important issues for its use as an extreme ultraviolet source in next generation lithography. We investigated the use of a magnetic field for controlling the kinetic energies of various species in a laser-produced tin plasma. 1.06μm, 8-ns pulses from a Nd:yttrium aluminum garnet laser were used to create the tin plasma in vacuum that expanded across a transverse magnetic field. Time-of-flight optical emission spectroscopy was used to measure the velocities of excited neutral and singly ionized tin species. Our studies showed a significant reduction in the kinetic energies of the plume species with a modest magnetic field of 0.64T.