Electron-beam focusing and deflection properties for misaligned dual gate field emitters

Field emitters are used as distributed electron sources in applications suc h as field emission displays (FEDs) and electron guns. The focusing and def lection of an electron beam may be achieved using dual gate structures. The fabrication process for such emitters involves self-aligning steps with ce rtain tolerances and also non-self-aligning steps. In this article, the eff ects of emitter structure misalignments on the device focusing properties a re studied. The simulation results have been obtained using the Simion 3D 7 .0 software package. The electron trajectories are very sensitive to the re lative position of the field emitter within the structure. An optimal posit ion of the focusing gate has been shown to exist even when this electrode i s misaligned with respect to the emitter.