A study of 157 nm resist design by using highly precise theoretical calculation of absorption spectra

Vacuum ultraviolet (VUV) absorption spectra of resist materials for 157 nm lithography were calculated theoretically by symmetry adapted cluster configuration interaction (SAC-CI) method. We have investigated several saturated hydrocarbons. It was found that SAC-CI calculations are quite close to the experimental values of absorption peak positions, and it has enough precision qualitatively to compare the absorption coefficient among different molecules. High precision prediction enables exact assignment of an absorption spectrum. It was found that SAC-CI calculation is very useful for the development of resist polymers and other component for 157 nm resists.