Optimum Geometry and Space-Charge Effects in Vacuum Microelectronic Devices
Cui Z.
A new numerical method is presented for the sim ulation of electrical characteristics of microemitter devices. The method, a combination of the boundary integral method and the finite difference method, is capable of dealing with arbitrary microemitter shapes and calculating space-charge effects. A spherical mesh structure has been used, which allows calculations with high resolution in the vicinity of a microemitter apex. Seven different shapes of microemitters have been simulated for the comparison of their field-enhancement factors. The optimum geometry of a microemitter is found to be a cusp-like shape. The space charge has an effect on field emission current only for current densities above 108 A/cm2. © 1993 IEEE