A FIELD EMISSION STUDY OF SILICON

Electron field emission experiments on silicon tips are presented. In the first part, FEM patterns and current-voltage characteristics are reported for an atomically clean surface, and thus for different values of heating and field emission temperatures. The thermal end forms show the formation of high index facets, whose dimensions are functions of the annealing temperature. The temperature dependance of the I-V characteristics is observed, and contributions of the electrons from the different bands (conduction, surface states, valence) are then deduced. In the second part, the oxidation of Si is followed starting from an exposure of a few Langmuirs. The oxidation is initiated at the vicinal regions and propagates inside the facets until the saturation. This progression is accompanied by a translation of the Fowler-Nordheim characteristics until the saturation. Finally and for both cases, the high stability of the current in function of the time is presented and discussed