Intense EUV incoherent plasma sources for EUV lithography and other applications

Intense visible and ultraviolet sources, both incoherent and coherent, have been used in a variety of commercial applications over the years. Perhaps two of the most far-reaching applications are in the areas of microlithography and materials processing. In microlithography, the mercury vapor discharge lamp has provided the illuminating flux for microlithography machines for over 20 years. More recently, excimer lasers are playing an increasing role in this field. In materials processing, because of flux requirements that will be discussed later, sources have been largely restricted to lasers. The available lasers cover a wide range of wavelengths and pulse durations and have become major industrial tools for a broad spectrum of applications. This paper will point out the role that intense extreme ultraviolet incoherent (nonlaser) sources might play in the future, in that they may be able to provide similar intensities to those presently provided only by lasers, but in a much simpler, more efficient way and, in semi systems, at a potentially much lower cost.