Abstract
Acid diffusion length has been regarded as the most important factor in the development of chemically amplified resists used for ultrafine patterning. In this study, the acid diffusion length in chemically amplified extreme ultraviolet (EUV) resists was investigated by a Monte Carlo method in the presence of quenchers. The acid diffusion length corresponding to the highest chemical gradient, which results in the lowest line edge roughness, was investigated by varying the exposure dose, the acid generator concentration, and the effective reaction radius for deprotection. Although the optimum acid diffusion length was decreased with the increase of effective reaction radius for deprotection, it did not depend on the exposure dose or acid generator concentration.