Transient Absorption Spectra of Electron Beam Sensitive Polyimides and their Model Compounds

Abstract

Transient absorption spectra of electron beam sensitive polyimides and their model compounds were measured by the nano second pulse radiolysis using a LINAC. Transient absorption bands at 550 nm and 760 nm were observed for the benzophenone-containing-polyimide, PI(BTDA/DEDPM) in THF solution, which are assigned to triplet state and radical anion, respectively. The radical anion was also observed even in CH2Cl2 solution as well as the absorption of radical cation, showing that strong electron affinity of imide moieties. The active intermediate of the pattern formation of PI(BTDA/DEDPM) was determined to be the triplet excited state.