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 single emitter with a real surface was investigated. The field emission pattern of the emitter did not show any symmetry which indicates a clean crystal structure of the surface; however, the highly nonlinear characteristics in log (I/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 voltage. The slope of log I sat vs 1/T plots gives an activation energy of 0.58 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 surface state to the conduction band are emitted.