PHYSICAL BASIS FOR APPLYING THE FOWLER-NORDHEIM J-E RELATIONSHIP TO EXPERIMENTAL IV DATA

The purpose of this work is to show that the Fowler-Nordheim (FN) curr ent-voltage (I-V) plot [log(I/V2) as a function of 1/V] must be treate d, on principle, as nonlinear. The cause of this behavior is outlined to be the fact that the electric field and current density are not con stant over the emitter's surface. Traditional approach of the FN I-V p lot as being linear may lead to physical contradictions. These contrad ictions are brought into light. A field emitter model is then develope d, which allows to express in closed analytical equations the above st atements. Expressions for field enhancement factor, area factor and al so for the I-V relationship are obtained. The FN I-V plot nonlineariti es are shown to be greater for smaller voltages. Within this model, th e FN I-V plot can be taken as quasilinear, under some assumptions. Sug gestions for technological parameter extraction from I-V data through nonlinear or linear least-squares optimization techniques are done.