Phenolic Based Molecular Glass Resists for Next Generation Lithography

The idea of using small molecules instead of polymers for next generation lithography has enabled improved resolution and line edge roughness (LER). Rather than using polymeric materials, we are focusing on a new class of materials known as molecular glasses. These are low molecular weight organic materials that demonstrate high glass transition temperatures despite their modest size. Unlike polymeric resists, these molecules have the added advantages of distinct size and uniformity. We have synthesized a series of molecular resists containing rigid aromatic backbones and phenolic moieties. An increase in glass transition temperature is observed with increasing size and rigidity. Glass transition temperatures (Tgs) between 80-130°C have been observed for resists with molecular weights within the range of 500-900g/mol. These phenolic based resists also show the high sensitivity and sub-50 nm contrast required of candidates for next generation lithography.