DFT Calculations of Photoabsorption Spectra for Alicyclic and Heterocyclic Compounds in the VUV Region

摘要

Time-dependent density functional theory (TD-DFT) calculations using the B3LYP hybrid functional were performed to predict transparencies of alicyclic and heterocyclic compounds in the vacuum ultraviolet (VUV) region. Model compounds of conventional and novel polymer platforms for F_2 lithography (157 nm) are devoted for calculations, and the calculated spectra demonstrate very low absorbance of highly fluorinated alicyclic and heterocyclic compounds and also show the effectiveness of introduction of -F and -CF_3 groups in reducing the optical absorption at the wavelength. In particular, devised fluorination, such as -CF_3 in close proximity of light-absorbing ester functionality, can significantly reduce the absorption of polymer platforms containign norborane, gamma-lactone, and delta-lactone structures.