ELECTRON-BEAM CHARACTERISTICS OF DOUBLE-GATED SI FIELD EMITTER ARRAYS

Double-gated Si field emitter arrays were fabricated in order to gener ate a focused electron beam and their characteristics were measured. T hese devices were fabricated by reactive ion etching followed by doubl e successive evaporation of insulating layer and electrode. In the pre sent device, the lower gate was used as an extraction electrode and th e upper one was used as an electrostatic focusing lens. The device pre sented here has a 1.2 mu m lower gate opening and a 2.2 mu m upper gat e opening, which are smaller than those reported previously by the aut hors (2 mu m lower gate openings). Beam characteristics such as emissi on current, focusing properties, spot size, and stability of the focus ed beam current are reported. (C) 1996 American Vacuum Society.