Temperature dependence of field-emission characteristics from a p-type Si single emitter with real surface

The temperature dependence of field-emission current from a p-type Si singl e emitter with a real surface was investigated. The field emission pattern of the emitter did not show any symmetry which indicates a clean crystal st ructure of the surface; however, the highly nonlinear characteristics in lo g(1/V-2) vs 1/V plots (F-N plots) commonly observed from a clean p-type Si emitter are obtained. The emission current at the gentle slope region of F- N plots (I-sat) shows strong temperature dependence at a fixed applied volt age. The slope of log I-sat vs 1/T plot,, gives an activation energy of 0.5 8 eV. The most probable conclusion is that the Fermi level is pinned at the middle of the band gap of the surface and electrons generated from the sur face state to the conduction band are emitted.