Electron field emission from cathodes with Si and SiGe nanoclusters

The peculiarities of electron field emission from Si cathodes with Si and SiGe nanoclusters have been investigated in details. To form Si nanoclusters on the flat surface or Si tips the LP CVD, IPS, or thermal evaporation methods were used for deposition of initial silicon enriched SiO_x (x≤1.5) films in the thickness range 2-10 nm. In some cases the amorphous ultrathin Si film has been deposited. During high temperature annealing the self-organized growth of the Si nanoclusters occurs in the films. The size and spatial density of the Si clusters depend on the initial film thickness, index stoichiometry (x) and annealing temperature. The Si clusters are imbedded into SiO₂ matrix or coated with ultrathin SiO_x shell. The nanometer sized SiGe nanoclusters were formed by MBE method. The peak of emission current and changing the slope in current-voltage characteristics have been observed in some cases. The appearance of the emission current peaks has been explained according to previously proposed theoretical model.