Thermalization Distance of Electrons Generated in Poly(4-hydroxystyrene) Film Containing Acid Generator upon Exposure to Extreme Ultraviolet Radiation

It is known that the chemical yield generated upon exposure to an ionizing radiation strongly depends on the thermalization distance of the electrons ejected through ionization. In this study, the acid yield upon exposure to extreme ultraviolet (EUV) radiation, the wavelength of which is 13.5 nm, was analyzed using a Monte Calro simulation of radiation-induced reactions. The thermalization distance in poly(4-hydroxystyrene), which is a typical backbone polymer of chemically amplified resists used for an ionizing radiation, was determined to be 3.2 ±0.6 nm. The reaction radius for the dissociative electron attachment to triphenylsulfonium triflate was also determined to be 0.70 ±0.08 nm.