Current Status and Perspective of EUV Lithography

The EUV lithography (EUVL) utilizes 13-nm photons as a light source. Because of the short wavelength, it provides a very high resolution and is applicable to the fabrication of multiple generations of semiconductor devices from 45 nm hp down to 32 and even 22 nm hp. This makes EUVL the most promising next-generation lithography, which will follow ArF immersion lithography. However, because the wavelength is so short, bringing EUVL to the level of a practical production tool involves many difficult challenges, such as the development of a high-power light source, high-precision reflective optics, low-defect multilayer masks, a high-resolution high-sensitivity resist, and so on. To overcome the technical difficulties and accelerate the development of EUVL, various projects have been launched and are currently running under the management of SEMATECH (US), NEDEA+ (Europe), and ASET and EUVA (Japan). These activities have produced great advances in EUVL technology in the past several years. A full-field exposure tool for process development (α tool) will be delivered in 2006, and an exposure tool for mass production (γ tool) will be delivered two or three years after that. This presentation gives an overview of recent progress in EUVL.