Novel resistive layer structure using via holes of an insulating interdielectric as a current path

Abstract

A novel resistive layer structure was proposed for a Mo-tip field emitter array, where the electrons travel along a resistive path running from a cathode electrode to a tip through nearest neighboring via holes of an insulating interdielectric film. To study the field emission characteristics of the new structure, Mo-tip arrays with a gate hole size of 1.2 mum were fabricated using a PH3 doped amorphous Si (a-Si:H) film as the resistive layer and a silicon oxide (SiOx) interdielectric film with 1.2-mum-diam via holes. Before the measurements of current-voltage characteristics, the arrays were annealed in an Ar environment, which is used for the vacuum packaging of a display panel. The arrays showed a strong dependence of an emission current on the resistive layer thickness, i.e., an average current density of 10 nA/tip at a gate voltage of 108, 93, and 82 V for a-Si:H film with a thickness of 0.36, 0.6, and 1.2 mum, respectively. The new structure exhibited a smaller voltage drop than that of a conventional mesh structure, with the gate voltage of the former being decreased by 35 V at a current density of 10 nA/tip. It was also found that the new structure was robust enough to sustain above 70 nA/tip, which is more than enough to be used for a wide variety of field emission display applications. The dependence of the resistivity of the a-Si:H on a sealing process was also discussed. (C) 2001 American Vacuum Society.