Random telegraph fluctuations in GaAs/Al0.4Ga0.6As resonant tunneling diodes

We have characterized discrete conductance switching noise in Resonant Tunneling Diodes (RTDs) fabricated on GaAs/Al0.4Ga0.6As material system. Temperature dependence of the high and low resistive states time constants indicated that the noise arises from thermal activation of electrons to localized states in the energy barrier. Both time constants are found to decrease with increasing negative bias at the emitter indicating that the noise is caused by hopping conduction of electrons from the energy barrier. The magnitude of the discrete conductance fluctuation is studied in detail. A model has been postulated in which the capture of an electron by a trap in the energy barrier causes fluctuations in the transmission coefficient of the electron due to the modulation of the local barrier potential. The computed step height based on the proposed model is compared to the experimental results. Excellent agreement between theory and experiment is observed.