Field emission from an ion-beam-modified polyimide film

We demonstrate the field emission of electrons from an ion-beam-modified po lyimide material. A 25-mu m-thick polyimide sheet is used as the starting m aterial. The electrical resistivity of this polyimide film is found to abru ptly decrease after Ar ion irradiation at doses higher than 5x10(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 ar e subsequently irradiated. An emission current of the order of CLA is obser ved at relatively low electric fields for the irradiated samples, while no emission is detected from unirradiated samples. An emission current stabili ty of 1.9+/-0.3 mu A is observed. The current-voltage characteristics of th e polyimide field emitters are compared with those of a field emitter made from a photoresist.