OBSERVATION OF INTRINSIC TRISTABILITY IN A RESONANT-TUNNELING STRUCTURE

A new technique has been developed to probe the region of apparent bis tability due to a tunneling resonance in the characteristic of a semic onductor asymmetric double-barrier structure. The measuring circuit us es a voltage supply designed to have a load line with positive slope, equivalent to a voltage source and negative series resistance. The app earance of bistability and hysteresis in the characteristic is an arti fact of the conventional measuring technique, which employs a load lin e with negative slope. The complete characteristic is found to be a co ntinuous Z-shaped curve between 50 and 150 K, corresponding to tristab ility. Equivalent circuit models for the device and voltage supply pre dict a narrow range of circuit parameters for which a static operating point exists inside the tristable region.