Flat-band Barrier Height Research Articles

Doping dependence of the Schottky-barrier height of Ti-Pt contacts to n-gallium arsenide

The barrier height and ideality factor of Ti–Pt contacts on n-type GaAs have been measured in the doping range Nd =3.3×1016 to 3×1018 cm−3. The flat-band barrier height, determined from capacitance-voltage measurements, is found to be independent of Nd whereas the effective barrier height for current transport, defined by the relation for thermionic emission, decreases rapidly at Nd >1×1018 cm−3. The results agree quite well with thermionic field-emission theory.

The problem of correlating Schottky-diode barrier height with an ideality factor using I-V measurements

Critical analysis is made of a recently proposed method of determining the relationship between the ideality factor and the barrier height of Schottky barrier diodes (SBD's) from I-V measurements. It is demonstrated that, while this method may produce consistent results in situations where a stable reproducible manufacturing process exists, the flat-band barrier height so determined cannot be taken to be the true flat-band barrier height.

Schottky barrier height and reverse current of the n-Si-electrolyte junction

We present a new set of results on the current-voltage and capacitance-voltage characteristics of the n-Si-aqueous electrolyte interface. The extreme sensitivity of these characteristics to surface defects has been realized, and defect-free surfaces have been obtained by using a mechanochemical polishing method. A transient technique has allowed us to measure the anodic current density for the oxide-free surface. We have performed these experiments for samples of various donor concentrations and electrolytes of various pH. In each case the flat-band potential and Schottky barrier height have been obtained. The results show that the process for anodic current is thermally activated electron transfer from surface states over the Schottky barrier, and not electron-hole pair generation in the depletion region, as was previously believed.

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

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 × 10 15 cm −3 to 2 × 10 18 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 = − χ m ϵ m where ϵ m is the maximum junction electric-field and χ m a characteristic length in the region of 20–40 Å.