Publications
Impact of photoacid generator leaching on optics photocontamination in 193-nm immersion lithography
Summary
Summary
Leaching of resist components into water has been reported in several studies. Even low dissolution levels of photoacid generator (PAG) may lead to photocontamination of the last optical surface of the projection lens. To determine the impact of this phenomenon on optics lifetime, we initiate a set of controlled studies...
Immersion patterning down to 27 nm half pitch
Summary
Summary
Liquid immersion interference lithography at 157 nm has been used to print gratings of 27 nm half pitch with a fluorine-doped fused silica prism having index of 1.66. In order to achieve these dimensions, new immersion fluids have been designed and synthesized. These are partially fluorinated organosiloxanes with indexes up...
Nanocomposite approaches toward pellicles for 157-nm lithography
Summary
Summary
Pellicle materials for use at 157 nm must display sufficient transparency at this wavelength and adequate lifetimes to be useful. We blended a leading candidate fluoropolymer with silica nanoparticles to examine the effect on both the transparency and lifetime of the pellicle. It is anticipated that these composite materials may...
Marathon evaluation of optical materials for 157-nm lithography
Summary
Summary
We present the methodology and recent results on the longterm evaluation of optical materials for 157-nm lithographic applications. We review the unique metrology capabilities that have been developed for accurately assessing optical properties of samples both online and offline, utilizing VUV spectrophotometry with in situlamp-based cleaning. We describe ultraclean marathon...