July 5, 2012 – BUSINESS WIRE — Gigaphoton Inc., lithography light source manufacturer, reached a maximum of 5.2% extreme ultraviolet (EUV) coversion efficiency (CE), beating the semiconductor manufacturing industry’s target of 5.0% for a first-generation EUV lithography scanner. These data show an average of 4.7% CE.
Gigaphoton uses tin (Sn) plasma as the EUV source and a proprietary pre-pulse laser technique. The laser-produced plasma (LPP) light source releases optimum EUV energy from the plasma by first irradiating a droplet of Sn with a short-wavelength, solid state laser as a pre-pulse, then irradiating the enlarged droplet with the main-pulse CO2 laser. This maximum CE of 5.2% was achieved with 150 mJ CO2 laser energy. It would be equivalent to 175W EUV output at 100kHz CO2 laser frequency.
Gigaphoton has been working on the development of LPP light sources for EUV lithography since 2002, investigating on-demand supply of Sn target droplets of <20µm diameter, an optimum combination of the short-wavelength solid state laser pre-pulse and the main CO2 laser pulse, as well as debris mitigation and removal using magnetic fields to protect the collector mirror. Also read: Gigaphoton extends DUV another generation, makes progress on EUV conversion efficiency
With production-level CE, Gigaphoton is progressing toward initial shipment of a mass production model. “To respond to the request for shipment of the EUV source, we at Gigaphoton have focused on R&D to prepare for our entry into the EUV business," said Hitoshi Tomaru, president of Gigaphoton.
Gigaphoton makes high-performance deep ultraviolet (DUV) laser light sources used by major semiconductor chipmakers and is developing LPP EUV technologies. See http://www.gigaphoton.com/e/index.html.