Failure Mode of Si Field Emission Arrays based on Emission Pattern Analysis

Large arrays of nanoscale silicon field emitters are tested in a UHV system equipped with a phosphor screen. The anode current is measured and the emission pattern is captured at the same time. The emission pattern shows the whole Field Emission Arrays (FEAs) are emitting from the beginning of the test. But as the test progresses, the regions at the edge of the array are more vulnerable and tend to be damaged/shorted first. A few shorted emitters along the edges could reduce the effective gate bias applied to the central region of the array, causing the emission current of the whole array to drop dramatically, and prompt the FEA to fail, while the physical integrity of majority emitters in the array are intact.