Quantitative Aspects of the Tunneling Resistance in <i>n</i>-GaAs Schottky Barriers

The influence of the doping level and the barrier height on the characteristics of the differential resistance of M/n-GaAs tunnel contacts has been investigated both theoretically and experimentally. The computation has been based on a pure WKBJ approximation and the quadrature over the momentum parallel to the interface was included. The position of the resistance maximum appears strongly dependent on the barrier height and insensitive to the value of the doping level. Vacuum-cleaved contacts have been made with various metals, i.e., barrier heights, for two different values of the carrier density. In spite of some systematic absolute discrepancies, the experimental variations of the differential resistance with the barrier parameters are in good agreement with theory.