The effect of Pd coating on electron emission from silicon field emitter arrays

Abstract

Uniform silicon tip arrays were fabricated using the reactive ion etching followed by the reoxidation sharpening, and the effect of Pd-coated layer on electron emission characteristics was studied. The electron emission from Si field emitter arrays (FEAs) was a little improved by removing surface oxide on the FEA, but pronounced drastically by coating 100-A-thick Pd metal layer. The turn-on voltage in the Pd-coated Si FEAs reduced by 30 V in comparison with that in noncoated ones. This is resulted from the increase of surface roughness at the tip apex by the Pd coating on Si FEA, via the decrease of the apex radius at which electrons are emitting. The Pd-coated emitters showed superior operating stability over a wide current range to that of the noncoated ones. This suggests that Pd coating enhanced the high temperature stability and surface inertness of Si FEA. (C) 2000 American Institute of Physics. [S0021-8979(00)01605-4].