Power scale-up of the extreme-ultraviolet electric capillary discharge source

Recent development work on the EUV electric capillary discharge source been has focused on two areas: increasing EUV power generation and minimizing debris deposition on plasma facing optics. To achieve high-power operation, a pulser capable of driving the source up to 1.7 kHz and a new high-power lamp have been integrated. An EUV flux of 9 W into p-sr and a 2 percent bandwidth has been generated in burst mode at 1000 Hz. Three additional parametric studies are discussed. The first compares the EUV power generation and spectral output for three different capillary materials. The second study compares the source efficiency for 3 mm and 6 mm length capillaries. And the third parametric study measures the EUV output stability over a one million pulse run. The second focus area has been to increase mirror reflectance lifetimes through the further development of the gas curtain debris mitigation approach. A new gas curtain laboratory has been built with more than a 10x increase in flow capability and a 10x reduction in chamber background pressure. Measurements of the gas curtain efficiency have demonstrated a reduction in particulate deposition rate of at least a factor of eighty.