Field emission properties of silicon field emitter arrays (Si-FEAs) with sputtered gate structures were described and analyzed about two different tip Structures surrounded by volcano-shaped gates. The resulted field emission characteristics showed that some of the emitted electrons are diverted to the gate structure because of the asymmetrical geometry of fabricated Si-FEAs with volcano-shaped gate structures. However, although the gate structures of fabricated FEAs had fragile and non-uniform edged shapes as a result of the shadow effect during sputtering and lift-off process in ultrasonic bath, it was possible to obtain stable field emission properties as a result of electrical aging effects on the edge of the non-uniform gate electrode as well as the surface of silicon tip after repeated measurements. From the Fowler-Nordheim (F-N) plots and F-N equations, it was confirmed that the field enhancement factor was abruptly changed through the electrical aging and was more influenced in case of the volcano-shaped lateral tip structure. (C) 2008 Elsevier B.V. All rights reserved.