EVALUATION OF MATERIALS FOR 193-nm LITHOGRAPHY

The explosive growth in performance of microelectronic devices has been made possible by steady advances in microlithography and photoresist technologies. Tremendous efforts to extend optical lithography beyond the 0.25 micrometer boundary, as currently obtainable with KrF-excimer lithography, are ongoing. Although some similarities exist between the imaging chemistries involved in the 248nm and 193nm lithographies, different materials are needed due to the distinct difference in optical absorbance requirements. Resist systems which can be developed with aqueous base would be preferred. However, it might well turn out that the targeted requirements can only be fulfilled by resist systems which involve some type of dry etch steps. This paper will focus on a positive tone resist system, which is based on novel silicon containing methacrylate polymers. Due to a unique combination of monomeric building blocks, polymers with high silicon concentrations and, at the same time, high thermal stability are obtained.