Fabrication of metal field emitter arrays for low voltage and high current operation

This article describes a new fabrication process for a metal field emitter to achieve low voltage and high current operation. The key element of the fabrication process is that the isotropic silicon etching and oxidation process used in silicon tip fabrication are utilized for gate hole size reduction and gate oxide layer formation. A reliable structure with a small gate hole can be easily obtained. Metal field emitter arrays were fabricated in order to demonstrate the validity of the new process and submicron gate apertures were successfully obtained from 2.25-mu m-diam disk patterns defined by a conventional contact mask aligner. The required gate voltage to obtain an anode current of a 0.1 mu A/tip was 54 V, and emission currents above 20 mu A/tip were stable at a gate bias of 96 V without any disruption. (C) 1998 American Vacuum Society. [S0734-211X(98)03502-1].