Electron and Hole Transfer in Anion-Bound Chemically Amplified Resists Used in Extreme Ultraviolet Lithography

The uniformity of acid generator distribution and the length of acid diffusion are serious problems in the development of resist materials used for the 16 nm node and below. Anion-bound polymers in which the anion part of onium salts is polymerized have attracted much attention for solving these problems. In this study, the reaction mechanism of an anion-bound polymer in cyclohexanone was clarified using pulse radiolysis. The design of an efficient electron and hole transfer system is essential to the enhancement of resist performance.