Direct nanopatterning of polyfluorene derivative is demonstrated using electron-beam lithography. Polyfluorene, which has attracted much attention because of its strong fluorescence and application in organic light emitters, is a negative (crosslinking) type material upon exposure to radiation, and requires a large amount of exposure dose ∼2300μC∕cm2 to be patterned in the present case. This extremely large dose would lead to radiation damage of the polymer. To address this issue, a polyfluorene derivative for acid-catalyzed chemical amplification was synthesized to realize nanopatterning of π-conjugated polymer without degrading its optical property. The synthesized polyfluorene derivative was investigated in terms of sensitivity, optical absorption, and spatial resolution. Sensitivity of 4μC∕cm2 was achieved, and lines of 70 nm width were fabricated after optimization of the process conditions.

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