Design and performance of EUV resist containing photoacid generator for sub-100 nm lithography

摘要

To fulfill the SIA roadmap requirements for EUV resists, the development of entirely new polymer platforms is necessary. In order to address issues like Line Edge Roughness (LER) and photospeed, we have developed a novel chemically amplified photoresist containing a photoacid generator (PAG) in the main chain of the polymer. The incorporation of a cationic PAG unit, phenyl methacrylate dimethylsulfonium nonaflate (PAG), in the resist backbone showed increased sensitivity, when compared with analogous blend PAG resist samples. In addition, the overall lithographic performance improved by using the counter anion (nonaflate) in the PAG units. The newly synthesized polymer bound PAG resist, poly (4-hydroxystyrene-co-2-ethyl-2-adamantyl methacrylate-co-PAG) showed sub-50 nm features using EUV Lithography.