Gigaphoton raises the bar with 20W EUV light source
The firm has made a critical step forward in realising LPP light sources for mass producing EUV lithography equipment
Gigaphoton has achieved EUV light output equivalent to a maximum of 20W for its laser-produced plasma (LPP) light sources for EUV lithography scanners.
This result was obtained by irradiating the tin target (tin droplet) with a solid-state pre-pulse laser and a CO2 laser at 100kHz. An average EUV output of 10W was confirmed during operation.
Considering that the current commercially accepted EUV output levels are around 10W, the results demonstrated by Gigaphoton represents that a critical milestone has been reached for pre-production level output. The firm is committed to continuing development efforts targeting 250W output.
Gigaphoton has focused on developing high output, stable, and economical LPP light sources since 2002. Since then, The company has introduced several unique technologies including the development of on-demand tin droplets generator with droplets measuring less than 20μm, the combining of short wavelength solid-state pre-pulse lasers and CO2 lasers as a main pulse and the utilisation of magnetic field for debris mitigation.
The recent achievement in reaching production level output are thanks to Gigaphoton's highly advanced technical capabilities and has brought the company one step closer to mass production level LPP light sources. The latest details of Gigaphoton's LPP light source technology will be presented at the SPIE Advanced Lithography 2013, being held in San Jose, California from February 24th through the 28th.
The unique LPP light source technology introduced by Gigaphoton extends the lifetime of droplet generators by utilising ultra-small tin droplets on-demand, reducing downtime and cost. In addition, high EUV output conversion efficiency has been achieved through the optimised 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 maximise 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.
"The fact that our unique LPP light source technology is now able to achieve the level of EUV output matching that of today's pre-production performance, proves that our vision for high output, low running cost, stable LPP light sources are indeed achievable," says Hitoshi Tomaru, President and CEO of Gigaphoton.
"Our efforts will help to bring the industry closer to realiaing mass production level EUV lithography scanners. We are making firm progress towards our entry into the EUV light source business - focusing on technology development to accommodate the future industry needs."
