Photoresists for CO2-based next-generation microlithography

Two routes have been pursued toward the fabrication of photoresists for next-generation micro lithography, using condensed carbon dioxide as the processing solvent. Addition polymers containing a norbornyl backbone were synthesized to include fluorinated moieties and chemical amplification switching groups. Other polymers, synthesized free radically in condensed CO2, include partially fluorinated backbones. These materials have been characterized and their lithographic properties evaluated. Solubility differences between exposed and non-exposed resist have been observed in these novel systems, which should provide the necessary contrast for high-resolution imaging.