Nitride-based thin-film cold cathode emitters

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

ABSTRACT

Cold cathodes have been fabricated using two different nitride structures as a thin film emitting layer. The AlN and graded AlGaN structures are prepared by metallorganic chemical vapor deposition (MOCVD) on an n-type 6H-SiC substrate. Individual aluminum grids are perforated with an array of either 1, 3, or 5μm holes through which the emitting surface is exposed. After device fabrication, a hydrogen plasma exposure was found to be necessary to activate the cathode. The devices have displayed a limited lifetime and a small percentage of the devices operate, although half of the devices with 5μm holes functioned. The highest measured collector currents are 0. 1μA for AlN and 10nA for AlGaN at grid voltages of 110V and 20V, respectively. The grid currents are typically 10 to 104 times the collector currents.

Publisher: Materials Research Society Symposium Proceedings,   Volume: 449,   1121-1126 ||  Published: 1997-01 ||   Read more...