Update of the development progress of the high power LPP-EUV light source using a magnetic field

Gigaphoton Inc. has been developing a CO2-Sn-LPP (LPP: Laser Produced Plasma) extreme ultraviolet (EUV) light source system for high-volume manufacturing (HVM) semiconductor lithography. Key components of the source include a high-power CO2 laser with 15 ns pulse duration and 100 kHz repetition frequency, a solid-state pre-pulse laser with 10 ps pulse duration and a magnetic field debris mitigation system. To achieve 330 W with long collector mirror lifetime and stable output, we improved the performance of key system components; especially, the laser beam quality at 26 kW CO2 laser output power by upgrading the CO2 laser beam transfer system, the conversion efficiency (CE) by the optimization of plasma-related parameters to now 6 %, the dose stability and suppression of small Tin (Sn) debris by upgrading the shooting control system, the collector mirror degradation rate by the optimization of H2 flow condition and changes in the EUV chamber structure. This paper presents the key technology update of our EUV light source.