COMPARISON OF A RATE-EQUATION MODEL WITH EXPERIMENT FOR THE RESONANT-TUNNELING DIODE IN THE SCATTERING-DOMINATED REGIME

A quasistatic rate-equation model for the resonant tunneling diode (RT D) is presented. In this model, the RTD is divided into three regions, each assumed in quasithermal equilibrium. The electron transfer betwe en states in adjacent regions, assumed to be by elastic tunneling, is then proportional to the probability that the initial state is occupie d and the final state is empty. Using this approach, we derive a small -signal equivalent circuit. The model parameters may be either calcula ted or measured in a fairly straightforward manner, as is demonstrated for an In0.53Ga0.47As/AlAs RTD. We find that the de characteristic an d ac behavior up to 4 GHz are modeled well; we also find that the meas ured and calculated parameters agree to approximately a factor of 2 ex cept in the vicinity of the current valley. We show that this approach is accurate enough to provide insight into the operation of the devic e, yields results that are simple enough to be suitable for ac circuit simulation, and should be valid as long as the frequency of the small -signal excitation is much less than the scattering rate. (C) 1998 Ame rican Institute of Physics. [S0021-8979(98)01014-7].