Solvent dependency of pentacene degradation for top-gate-type organic ferroelectric memory

To minimize the degradation of pentacene films in the fabrication of top-gate-type MFS FETs (metal-ferroelectric-semiconductor field-effect transistors), the characteristics of four solvents which are used for overcoating organic ferroelectric films on pentacene films are investigated by dipping pentacene MOS diodes in these solvents. Then, using appropriate solvents such as 1,4-dioxane, MFS diodes composed of Au, P(VDF-TrFE) (poly(vinylidene fluoride-trifluoroethylene)), and pentacene are fabricated, and then C–V (capacitance vs. voltage) characteristics are investigated. It is concluded from comparison of C–V and data retention characteristics of the top- and bottom-gate-type MFS diodes that degradation of the pentacene film is insignificant when an appropriate solvent is used.