Gigaphoton Reports Successful Continuous Operation of EUV Lithography Scanner LPP Light Source

Gigaphoton, Inc. a major lithography light source manufacturer, announced today that it has successfully achieved 2 hour continuous operation of its laser-produced plasma (LPP) light source for EUV lithography scanners. This milestone was confirmed using a prototype LPP system which generates EUV light by irradiating Tin (Sn) Droplets with a solid-state pre-pulse laser and a CO₂ main pulse laser.

The Tin debris generated from the irradiation is mitigated through the combination of a high power superconducting magnet and Sn etching using H2 gas. The 2 hour continuous operation produced an averaged output power of 5W at 2% conversion efficiency (CE). Considering the current commercially accepted EUV output level is around 10W, the results demonstrated by Gigaphoton represents that yet another critical milestone has been reached for achieving initial production level laser performance. Gigaphoton is committed to continuing its development efforts targeting 250W output.

Gigaphoton has focused on developing unique technologies that enable high output, stable, and economical (cost effective) LPP light sources since 2002. Since that time, Gigaphoton has introduced several unique technologies including the development of droplet-on-demand systems with each Tin droplet measuring less than 20μm, the combined use of short wavelength solid-state pre-pulse and CO₂ main pulse lasers, and the use of high power superconducting magnets for debris mitigation. The recent achievement in reaching production level output can be attributed to Gigaphoton’s highly advanced technical capabilities and has brought the company one step closer to the mass production of LPP light sources.

The unique LPP light source technology introduced by Gigaphoton extends the lifetime of droplet generators by utilizing ultra-small Tin droplets on-demand, reducing downtime and cost. In addition, high EUV output conversion efficiency has been achieved through the optimized combination of short wavelength solid-state pre-pulse laser and CO₂ laser as the main pulse. This technology contributes to the real possibility of achieving efficient, high output EUV light sources. In order to maximize the life of the collector mirror, a superconducting magnet is used to generate a powerful magnetic field that guides the unwanted debris resulting from the thermal expansion of the Tin droplets towards the tin catcher. This results in further reduction of cost and downtime.

“I am very pleased with the progress we have made in achieving 2 hours of continuous operation using our unique LPP light source technologies. This further proves that our vision for high output, stable, and economical LPP light sources is real,” said Hitoshi Tomaru, President and CEO of Gigaphoton. “We will continue our efforts to help to bring the industry closer to realizing EUV lithography tools for HVM.”