Field Emission from an Ion-Beam-Modified Polyimide Film

We demonstrate the field emission of electrons from an ion-beam-modified polyimide material. A 25-µm-thick polyimide sheet is used as the starting material. The electrical resistivity of this polyimide film is found to abruptly decrease after Ar ion irradiation at doses higher than 5×10 15 cm -2 . To prepare a field emitter array, a pyramid-like structure is fabricated directly on the polyimide sheet using oxygen-plasma etching, and Ar ions are subsequently irradiated. An emission current of the order of µA is observed at relatively low electric fields for the irradiated samples, while no emission is detected from unirradiated samples. An emission current stability of 1.9±0.3 µA is observed. The current-voltage characteristics of the polyimide field emitters are compared with those of a field emitter made from a photoresist.