Determination of the doping profile near the metal-semiconductor interface of ZrN/GaAs contacts

The reduced capacitance and increased barrier heights observed for ZrN Schottky contacts to n-GaAs annealed from 700 to 850°C suggest the progressive formation of a metal-p⁺-n diode. Since the position of the potential maximum varies with the applied voltage, the effective active profile of the p⁺ region can be determined by combining capacitance-voltage and current-density-voltage measurements. The analysis assumes only that the depletion approximation holds and the current is dominated by thermionic emission. When this analysis was applied to ZrN/GaAs Schottky contacts, it was found that the p⁺ region had penetrated more deeply into the n-type substrate as the annealing temperature was increased, consistent with the formulation of a metal-p⁺-n diode