Novel Material Development for EUV Resist towards sub-20nm half pitch

Extreme Ultra-Violet (EUV) lithography is considered as one of the most promising candidates for next generation lithography (NGL) that can print sub-20nm half pitch. In order to implement EUV technology for actual device production, resist material is one of the critical items that require significant improvement in overall performance. Current most challenging technical requirement is the simultaneous improvement in resolution (R), line width roughness (L) and sensitivity (S). In order to achieve this requirement, many research groups are developing novel materials such as molecular glass[1],[2], polymer bound photo-acid generator (PAG)[3], high quantum yield PAG[4], sensitizer[5] and high absorption resin[6]. In this study, we focused on innovative PAG material development through the investigation of PAG acid diffusion length and PAG anion structure. Also, novel molecular resist consisting of protected Noria has been developed and its feasibility demonstrated. As the results of this study, it was found that PAG plays key function in order to achieve simultaneous RLS improvement. Additionally, it turned out that molecular resist protected Noria has high potential towards sub-20nm resolution. This study is hoped to contribute to the EUV resist development at sub-20nm half pitch generation.