Laser-produced-plasma light source development for extreme ultraviolet lithography

Abstract

The development status of our laser produced plasma EUV light source is reported including the xenon jet system and the 500 W laser system. Laser parameter optimization, for example, laser pulse energy, pulse width, and laser spot size, is ongoing to improve the conversion efficiency and EUV output power. A maximum conversion efficiency of 0.53% is obtained with a 50 μm diam target. The EUV output stability is analyzed based on spatial fluctuations of the Xe jet and the laser beam. In addition, a Xe ion exposure measurement has been started to investigate the collector mirror damage mechanism.