Tao Y, Tillack M S, Harilal S S, Sequoia K L, Burdt R A, Najmabadi F
Department of Mechanical and Aerospace Engineering and the Center for Energy Research, University of California, La Jolla 92093-0438, USA.
Opt Lett. 2007 May 15;32(10):1338-40. doi: 10.1364/ol.32.001338.
A thin Sn film was investigated as a mass-limited target for an extreme ultraviolet (EUV) lithography source. It was found that those energetic ions that are intrinsic with the mass-limited Sn target could be efficiently mitigated by introducing a low-energy prepulse. High in-band conversion efficiency from a laser to 13.5 nm EUV light could be obtained using an Sn film with a thickness down to 30 nm when irradiated by dual laser pulses. It was shown that the combination of dual pulse and inert Ar gas could fully mitigate ions with a low ambient pressure nearly without the penalty of the absorption of the EUV light.
