February 13, 2012 — Lithography light source maker Gigaphoton, Inc. achieved 7W of extreme ultra violet (EUV) power on its mass-production laser-produced plasma (LPP) light source, scheduled to be shipped in 2012.
The LPP light source meets requirements for high-volume manufacturing by combining sophisticated elemental technologies previously verified in experimental systems. Gigaphoton has already started operating a factory dedicated to initial mass-production of LPP light sources for shipment in 2012, said Dr Yuji Watanabe, president of Gigaphoton.
The 7W milestone was achieved with an approximately 20µm-diameter Sn target (tin droplet) irradiated by a combination of solid-state laser pre-pulse and 2.7 kW, 90kHz carbon dioxide (CO2) laser main pulse. A maximum of 0.3mJ, 27W EUV light was obtained at the plasma point running the LPP light source at 30% duty cycle for one hour. This lower level of power can be used for initial testing of current production systems.
Following the release of EUV energy, remaining Sn debris — fragments and atoms — could be deposited on the collector mirror. Because Sn ions damage the mirror’s multi-layer film, lowering reflectance and power output, establishment of a debris mitigation technology to protect the collector mirror from all debris is essential. Stable Sn droplet generation over an extended period of time, accurate positioning in three dimensions and precise timing control of the droplets are equally critical challenges in manufacturing these EUV sources for volume production.
Gigaphoton’s magnetic debris mitigation technology combines the pre-pulse generated by a solid-state laser and the main pulse generated by a CO2 laser to suppress generation of any Sn fragments and neutral Sn atoms by ionizing most of the material in each droplet. These ionized particles flow to the Sn catcher magnetically and are removed, minimizing deposition and potential damage to the collector mirror. The company’s on-demand droplet supply technology includes an innovative nozzle enabling a stable on-demand supply, timing control, and emission direction control.
Gigaphoton’s development program for LPP light sources for EUV lithography has been underway since 2002. Gigaphoton will continue its development program, aiming for an output of 250 W. Gigaphoton’s EUV technologies are being presented at SPIE Advanced Lithography 2012, this week in San Jose, CA.
Gigaphoton develops user-friendly, high-performance DUV laser light sources used by major semiconductor chipmakers. See http://www.gigaphoton.com/e/index.html.