SIO2-INDUCED SILICON EMITTER EMISSION INSTABILITY

An emission instability attributed to an oxide layer on a silicon emitter tip surface has been characterized. The instability leads to a current runaway which often results in device failure. When device failure does not occur, the instability is a one time event while the device remains in a vacuum environment. The magnitude of the instability increases with increasing oxide thickness and can be effectively eliminated by etching in buffered HF immediately before testing or device packaging.