Approach to next-generation optical lithography

We discuss the possibility of using optical lithography when the design siz e 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 (1 21 nm), and the extreme ultraviolet (EUV) (13 nm) indicate that the ArF exc imer laser can be used up to the 100 nm generation and that the lithographi c 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.