Sensitization Distance and Acid Generation Efficiency in a Model System of Chemically Amplified Electron Beam Resist with Methacrylate Backbone Polymer

For the development of resist materials for postoptical lithographies, the suppression of acid diffusion and the enhancement of the acid generation efficiency are required to meet both resolution and sensitivity requirements. In this study, we analyzed the acid yield generated in polymethylmethacrylate (PMMA), which was used as a model system for chemically amplified resists. For ionizing radiations such as electron beam and extreme ultraviolet radiations, polymers play an essential role in the generation of secondary electrons and protons. Therefore, a basic understanding of polymer radiation chemistry is important for the development of high-performance resists. We clarified the acid generation mechanisms including the initial electron distribution and the limit of acid generation efficiency in PMMA

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