FIELD-EMISSION FROM SILICON THROUGH STABLE CONTAMINANT LAYERS

Silicon field emitter arrays have been studied by field emission curre nt-voltage measurements as well as by direct FEM and FIM imaging. A ty pical stable current of 1 muA per emitter was measured at extraction v oltages of about 150 V. The data yielded a linear Fowler-Nordheim plot ; however, an irreversible and abrupt change of slope was observed in the early stage of field emission upon the first increase in field. Su bsequently stable and reversible, but displaced, F-N plots were obtain ed. We postulate that this phenomenon is due to a self-regulating proc ess that forms a thin stable contaminant on the emitting surface. This hypothesis was tested under controlled conditions using single emitte rs and found to be self-consistent.