THEORY OF ASYMMETRY IN THE CURRENT-VOLTAGE CHARACTERISTICS OF LATERALLY GATED SUBMICRON RESONANT-TUNNELING DIODES

We investigate the current-voltage characteristic I(V) of a sub-micron resonant tunneling diode with a lateral gate fabricated around the to p contact. The application of a negative bias voltage to the lateral g ate produces a confining potential in the plane of the barriers. This potential leads to the formation of zero-dimensional states in the emi tter accumulation layer and in the potential well. Because the lateral gate is nearer the accumulation layer than the potential well, the de gree of lateral confinement is different for electrons in the emitter and in the well. Using two-dimensional parabolic potentials with diffe rent characteristic frequencies to model the lateral confinement poten tials and a simple model for the longitudinal potential variation, we calculate the current-voltage characteristic for the device within the Bardeen transfer Hamiltonian formalism. Our theory reproduces all the essential features of experimental I(V) plots and in particular accou nts for the observed asymmetry under reversal of the bias voltage V.