Immersion lithography: New opportunities for semiconductor manufacturing

Immersion lithography has recently emerged as the preferred lithography solution for manufacturing the next generation of semiconductor devices (likely to address the 65, 45, and possibly the 32 nm nodes). Full-field immersion scanners operating at λ=193nm with de-ionized water as the immersion fluid have been recently demonstrated. In this article we report imaging results from the AT1150i prototype, a 0.75 numerical-aperture full-field scanner from ASML. We experimentally confirm the depth-of-focus improvements that immersion enables, and explore the implications of this gain for semiconductor manufacturing. This article also highlights the challenges the technology faces before it can be successfully introduced for semiconductor manufacturing. We pay particular attention to defects, in the form of particles, bubbles, and other processing residues, and highlight evaporation as a key mechanism underpinning these challenges. © 2004 American Vacuum Society.