Exploring the capabilities of immersion lithography

Immersion lithography has recently emerged as the leading candidate for extending 193 nm lithography to the 45 nm lithography node and beyond. By immersing the wafer in a high index fluid, lens designs with numerical apertures (NAs) approaching the refractive index of the fluid are possible. In this paper, the fundamental imaging physics of immersion lithography will be described. The impact of resolution and depth of focus will be explored, as well as the subtle though significant influence of hyper NAs on polarization related imaging