Yoshinori Funaki

Advanced materials for 193-nm resists

Acrylate monomers containing alicyclic side chains featuring a series of polar substituent groups were assumed to be model compounds. Solubility parameters were calculated for the corresponding acrylate polymers. These acrylate monomers were synthesized using a novel aerobic oxidation reaction employing N-hydroxyphtalimide (NHPI) as a catalyst, and then polymerized. These reactions were confirmed to be applicable for the mass-production of those compounds. The calculation results agreed with the hydrophilic parameters measured experimentally. Moreover, the relationship between the resist performance and the above-mentioned solubility parameter has been studied. As a result, a correlation between the resist performance and the calculated solubility parameter was observed. Finally, resolution of 0.13-micron patterns, based on the 1G DRAM design rule, could be successfully fabricated by optimizing the solubility parameter and the resist composition.

Novel molecular glass photoresist materials for next-generation lithography

A series of Adamantanephenol derivatives was synthesized from adamantinetriphenol / adamantinetrimethylhydroquinone and vinylether compound. Solubility for resist solvent or alkali developer of those materials and thermal properties were examined. Adamantanetrimethylhydroquinone cross-linked with divinylether (AmHQ-CL) had excellent properties as positive tone resist material. We evaluated lithographic properties of AmHQ-CL with photo acid generator and base. Line and space pattern was formed with EB exposure followed with post exposure bake and alkali development. Pattern of smooth wall surface was obtained by removing high molecular weight component from AmHQ-CL. Line width roughness (LWR) of the pattern AnHQ-CL nMWD was less than 30 nm. It was very small value compared with that of traditional polymer resist.

193-nm single-layer resists based on advanced materials

Recent advances in the 193-nm single-layer resist for forming finer patterns have led us to search for new resist materials for the ArF excimer laser. We describe novel, mass productive single layer resist based on hybrid hyper lactonic polymer which has high resolution, good hydrophilicity, and dry etch resistance. Further, we investigate the lactonic polymer, which has Mass-productive Ultimate Norbornyl group with Outstanding Solubility (MUNGOS).