Inhomogeneity of PAGs in resist film studied by molecular-dynamics simulations for EUV lithography

摘要

EUV resist materials are requested simultaneously to improve the resolution, line-edge roughness (LER), and sensitivity (RLS). In a resist film inhomogeneous structures in nanometer region may have large effects on directly the resolution and LER and indirectly on sensitivity. Inhomogeneity of PAGs in a hybrid resist for EUV lithography was investigated using molecular dynamics simulations. The hybrid resist film showed the inhomogeneous positions and motions of PAG cations and anions. Free volumes in resist matrix influence the motions of PAGs. Molecular structure such as bulky phenyl groups of a PAG cation localize the positions and reduce the motion of a cation. Chemical properties such as ionic interactions and lone-pair interaction also play an important role to determine the inhomogeneity of PAGs. Fluorine interaction enables active motions of PAG anions.