ABSTRACT
FIGURE 8.2 Typical view of a cell in a gated FEA (a) without and (b) with an integrated beamfocusing electrode. (Adapted from Temple D., Mater. Sci. Eng. R 24, 185, 1999. Copyright 1999: Elsevier. With permission.)
FIGURE 8.3 SEM images of various variants of designed Si-based cold cathodes. ([a,b] From Huq S.E. et al., J. Vac. Sci. Technol. B 16, 796, 1998. Copyright 1998: American Vacuum Society. With permission. [c,d] From Wisitsora A. et al., Appl. Phys. Lett. 71, 3394, 1997. Copyright 1997: AIP Publishing. With permission. [e] From Xu N.S. and Huq S.E., Mater. Sci. Eng. R 48, 47, 2005. Copyright 2005: Elsevier. With permission. [f] From Debski T. et al., J. Vac. Sci. Technol. B 18, 896, 2000. Copyright 2000: American Vacuum Society. With permission.)
microtip, the electron extractor gate with an aperture hole must be placed very close to the emitter. Some redundancies are also built into the array to take account of the fact that not all the microtips will be producing an equal amount of current. In order to enhance the lifetime of micro fabricated emitters, FEA configuration should provide efficient operation at low current levels (fraction of a μA/microtip).
