kW-class picosecond thin-disc prepulse laser Perla for efficient EUV generation

摘要

The technology for extreme ultraviolet (EUV) lithography sources is maturing. Laser produced plasma (LPP) sources with usable power >100 W have been used in high-volume manufacturing (HVM) applications, and 250-W sources are expected to be introduced in HVM soon. However, a further increase of power and cleanness may benefit a powerful picosecond (ps) laser in the near-infrared and wavelength converted spectral region. The HiLASE Centre has been working in thin-disc laser technology and has demonstrated a 0.5-kW platform Perla-C based on a very compact Yb:YAG regenerative amplifier. 100-kHz ps operation has been achieved with a fundamental spatial mode and excellent long-term pointing and energy stability. It is reported on a thin-disc-based ps Yb:YAG solid-state laser technology platform Perla developed in the Czech Republic and the present performance of delivering >4 mJ, <2-ps pulses at a 100-kHz repetition rate with the potential to be upgraded to 1 kW of average power and 1 -MHz pulse repetition rate. The ps laser extendibility is important for kW-class LPP sources and controlled free electron laser EUV sources in 10-kW power region.