Extreme Ultraviolet Lithography Light Source Research Articles

Laser Produced Plasma for EUV Light Source For Lithography

We describe properties of laser produced plasmas (LPP) for extreme ultra violet (EUV) light source for next generation lithography as an industrial application of LPP. We briefly present three topics related to the LPPEUV light source; laser intensity dependence of conversion efficiency from laser light to EUV light with 13.5nm wavelength with 2% bound width with tin target, present understanding of EUV emission from xenon target, and atomic processes in those targets.

EUV Light Source Development Project at EUVA and Research Collaboration between Universities and Industry.

The extreme ultraviolet (EUV) light source development project of the EUVA and the research collaboration between industry and universities are described. The development of EUV light sources using both laser produced plasma and discharge produced plasma is currently under way. The goal of four-year project is to attain 10 W output power at an intermediate focus point which should satisfy all the requirements of the EUV lithography light sources. The collaboration with universities will expand next year under the new research framework of the leading program of laser-based EUV sources.

Extreme ultraviolet emission from Xe clusters excited by high-intensity lasers

The property of extreme ultraviolet (EUV) generation from Xe clusters irradiated with intense lasers was studied. The Xe cluster jet was well characterized by the interferometric method. In order to obtain the adequate irradiation condition for strong EUV generation, EUV spectra were taken with various laser systems. Then, the wavelength, the pulse width, and the pump energy were widely varied. Through this survey, even with the comparatively low-density Xe jet of ⩽5×1018 cm−3 average atomic density, the highest conversion efficiency of over 10% from laser energy to EUV (5–18 nm) was obtained with a subpicosecond KrF laser pulse, where a 4π source was assumed. This EUV source is considered to be attractive as an EUV lithography light source because of its low average atomic density and small Xe cluster.