抄録
The current status of the laser produced plasma light source development for EUV lithography is presented. Our key technology is based on an RF-excited CO2 driver laser combined with a Sn droplet target, because this approach enables cost-effective high-conversion efficiency. The RF-excited CO2 laser has a MOPA (master oscillator power amplifier) configuration. It currently generates an average output power of 2.6kW at 130kHz repetition rate. Due to negligible wavefront distortion of the laser beam during amplification, a laser focus of 100μm (FWHM) has been obtained. The Sn target and magnetic ion mitigation development as well as an evaluation of the collector mirror lifetime are presented.
