EMISSION CURRENT SATURATION OF THE P-TYPE SILICON GATED FIELD EMITTERARRAY

Current-voltage (I-V) characteristics, current stability, and capacita nce-voltage (C-V) characteristics of p-type Si gated field emitter arr ays (FEAs) have been measured. Emitter tips were made on a p-type Si s ubstrate with a resistivity of 100 Omega cm. From experimental results , emission current saturation was found to occur beyond similar to 2 m u A and an inversion layer was found to be present under the gate. The emission current was also found to be much more stable than n-type Si FEAs. A model to explain the present I-V characteristics was derived, based on current limitation by thermal carrier generation in depletio n layers under both the tips and the gate. In this model, the inversio n layer acts as an n-channel gathering the thermally-generated electro ns under the gate and supplies them to the tips. A concept for a new F EA capable of actively controlling the emission current is proposed. ( C) 1996 American Vacuum Society.