Fluorous solvent-soluble imaging materials containing anthracene moieties

J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1252-1259 Fluorous solvent-soluble, photoreactive polymers were designed using the photodimerization of anthracene moieties. Four random copolymers with M_n=20,000-27,000 were synthesized, involving an anthracene-containing monomer and a fluorinated methacrylate with varying compositions. The polymers showed sufficient solubility in the fluorous solvents but were rendered insoluble by UV irradiation. One of the copolymers, FSIM-2, shows promise as a photoreactive imaging material for the photolithographic patterning of OLED pixels.

Highly fluorinated photoresist polymers that can undergo photodimerization reactions were designed using an anthracene-based monomer. Through the random radical copolymerizations of 6-(anthracen-9-yl)hexyl methacrylate (AHMA) and semiperfluorodecyl methacrylate (FDMA) with four different compositions, polymers with M_n=20,000-27,000 (M_w/M_n=2.0-2.9) were prepared in benzotrifluoride. The polymers, in particular fluorous solvent-soluble imaging material-2 (FSIM-2), showed sufficient solubility in fluorous solvents, including hydrofluoroethers, but were rendered insoluble by UV exposure (365 nm). This photochemical solubility change was evaluated quantitatively by a quartz crystal microbalance technique, along with tracing the chemical reaction by UV-vis spectroscopy. Finally, FSIM-2 and fluorous solvents were applied to the photolithographic patterning of organic light-emitting diode pixels. In the patterning protocol involving the lift-off of resist films in fluorous solvents, FSIM-2 was recognized as a promising photoreactive material when compared with a reference polymer P(FDMA-MAMA), which necessitates acidolysis reactions for lithographic imaging.