Development progress of Gigaphoton’s LPP EUV light source for inspection systems

Gigaphoton Inc. presents a Sn-LPP EUV light source for mask inspection tools. This light source uses a minimum-mass Sn droplet generator with an in-line Sn fuel supply system, a double-pulse laser irradiation scheme with precise shooting control and a debris mitigation technology with H₂ buffer-gas flow. During 1500 hours of continuous operation, a brightness of 120W/mm²sr at the plasma point, a stable EUV energy 3σ-value below 5% and a high availability of 99% have been obtained without reflectivity degradation of the EUV collector mirror. We are currently developing key components for higher repetition rate to further increase the brightness.