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Extremely narrow-bandwidth high-repetition-rate laser for high-NA step-and-scan tools

In this paper we discuss several resonator designs in terms of bandwidth, efficiency and lifetime of the major optical components. Experimental data are presented for a resonator combining the advantages of a long lifetime grating and etalon elements. Moreover, the limitations of these elements are overcome through the outcoupling scheme, ensuring optimum feedback over gas and tube lifetimes. In addition to low cost-of-ownership, this same resonator provides for an extremely narrow bandwidth ArF excimer laser development, using a single oscillator.