Understanding the Failure Mechanisms of Silicon Gated Field Emitters

Gated field emitter arrays (GFEAs) can fail due to various mechanisms which are not well understood. In this paper, several proposed failure mechanisms are investigated using simulation and experiment. The modelling performed using CST considers an ion bombardment zone to calculate the locations and number of ions that hit the emitter tip apex. As the starting location of the ions moves away from the tip, the fraction hitting the tip apex increases until $5\mu \mathrm{m}$ from the tip and then decreases until only ions born directly above the tip impact. Electrical measurements of arcs show that arcs only occur during forward bias with emission rather than in reverse bias indicating the mechanism is not surface breakdown.