AVS 46th International Symposium
    Flat Panel Displays Topical Conference Monday Sessions
       Session FP-MoA

Paper FP-MoA3
The Effect of Carbon Deposit on Electron Beam Degradation of Oxide Thin Film Phosphors

Monday, October 25, 1999, 2:40 pm, Room 604

Session: Luminescent Thin Films
Presenter: C. Kondoleon, University of Florida
Authors: C. Kondoleon, University of Florida
B.L. Abrams, University of Florida
J. Thomes, University of Florida
P. Rack, Rochester Institute of Technology
V. Krishnamoorthy, University of Florida
P.H. Holloway, University of Florida
Correspondent: Click to Email
The cathodoluminescence (CL) brightness and spectral distribution from thin film Ta@sub2@Zn@sub3@O@sub8@ has been studied as a function of electron dose. Thin films of Ta@sub2@Zn@sub3@O@sub8@ were prepared by sputtered deposition followed by rapid thermal annealing (RTA). Under bombardment by 2keV electrons, the films produce a blue luminescence with a dominate wavelength of 386nm. These films were exposed to residual vacuum gas dominated by H@sub2@ and H@sub2@O at pressures ranging from 10@super-8@ Torr to 10@super-6@ Torr with <5% loss in CL brightness. However when hydrocarbons from colloidal graphite paint was introduced and raised the base pressure of the vacuum from 1 x 10@super-8@ Torr to 8 x 10@super-8@ Torr, the CL brightness was degraded to 5% of its original value after approximately 4 hours at 2.7 x 10@super-4@ A/cm@super2@ (corresponding to a dose of 3.9 C/cm@super2@). The electron beam stimulated degradation since when the beam was off, degradation stopped. In addition, on some samples the electron beam was blocked by a Cu grid over the surface and degradation only occurred when the electron beam struck the surface. Auger analysis showed a thick layer of carbon. It is speculated that the electron beam cracked hydrocarbons, resulting in deposition of a carbonaceous layer which attenuated primary electrons and absorbed luminescent photons. The significance of this phenomena in field emission displays will be discussed. This work is supported by DARPA Grant MDA 972-93-1-0030, through the Phosphor Technology Center of Excellence.