Thin films of aluminum nitride and aluminum gallium nitride for cold cathode applications

Contributors:   A.T. Sowers, J.A. Christman, M.D. Bremser, B.L. Ward, R.F. Davis, and Robert J. Nemanich

ABSTRACT

Cold cathode structures have been fabricated using AlN and graded AlGaN structures (deposited on n-type 6H-SiC) as the thin film emitting layer. The cathodes consist of an aluminum grid layer separated from the nitride layer by a SiO2 layer and etched to form arrays of either 1, 3, or 5 μm holes through which the emitting nitride surface is exposed. After fabrication, a hydrogen plasma exposure was employed to activate the cathodes. Cathode devices with 5 μm holes displayed emission for up to 30 min before failing. Maximum emission currents ranged from 10-100 nA and required grid voltages ranging from 20-110 V. The grid currents were typically 1 to 104 times the collector currents.

Publisher: Applied Physics Letters,   Volume: 71,   2289-2291 ||  Published: 1997-10 ||   PDF (425.39 KB) ||   Read more...