Doping dependence of the barrier height of palladium-silicide Schottky-diodes

Abstract

Capacitance-voltage and current-voltage measurements have been used to determine the barrier height of palladium-silicon Schottky diodes. All diodes were heat-treated to form palladium silicide and the doping range of the silicon was varied in the range 5 × 1015 cm-3 to 2 × 1018 cm-3. The zero-electric-field (flat-band) barrier height was found to be independent of doping concentration in the above range, having a value 0·75 ± 0·01 eV. On the other hand the zero-bias barrier height is more electric-field dependent than the predictions of the usual image-force theory. However, the results are well described by an additional barrier lowering term of the approximate form Δφ = -χmε{lunate}m where ε{lunate}m is the maximum junction electric-field and χm a characteristic length in the region of 20-40 Å. © 1971.