Approach to next-generation optical lithography

We discuss the possibility of using optical lithography when the design size is below 130 nm. Our optical simulations at the laser wavelengths of KrF (248 nm), ArF (193 nm), F-2 (157 nm), Kr-2 (146 nm), ArKr (134 nm), Ar-2 (121 nm), and the extreme ultraviolet (EUV) (13 nm) indicate that the ArF excimer laser can be used up to the 100 nm generation and that the lithographic tool most suitable for the 70 nm generation is an ArKr laser system with a numerical aperture larger than 0.65. They also indicate that EUV sources will be needed for the 50 nm generation and that high-contrast resists will be needed for the 70 nm generation and beyond.