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 H-2 flow condition and changes in the EUV chamber structure. This paper presents the key technology update of our EUV light source.