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

Uniform silicon tip arrays were fabricated using the reactive ion etching f ollowed 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 ox ide 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 comp arison with that in noncoated ones. This is resulted from the increase of s urface roughness at the tip apex by the Pd coating on Si FEA, via the decre ase of the apex radius at which electrons are emitting. The Pd-coated emitt ers showed superior operating stability over a wide current range to that o f the noncoated ones. This suggests that Pd coating enhanced the high tempe rature stability and surface inertness of Si FEA. (C) 2000 American Institu te of Physics. [S0021-8979(00)01605-4].