ANALYSIS OF ELECTRON-EMISSION DEGRADATION IN SILICON FIELD EMITTER ARRAYS

Degradation of electron emission characteristics in single-crystalline and polycrystalline silicon field emitter arrays and its mechanism ha ve been studied. A critical biasing time t(c) at which the emission cu rrent started to be degraded dominantly was observed at a pressure of 5 x 10(-7) Torr. The t(c) is shortened as the emission current increas es. Also, the emission current repeatedly measured within t(c) with a complete relaxation after each measurement would not be degraded even though the total biasing time exceeded the critical time. The experime ntal results indicate that the degradation in silicon held emitters ma inly originates from thermal instability of the silicon tips, especial ly a decrease in the effective emitting area rather than changes in th e work function and geometrical factor. (C) 1998 American Vacuum Socie ty. [S0734-211X(98)08802-7].