Influence of the barrier thickness on the noise performance of AlAs/GaAs/AlAs double barrier resonant tunneling diodes

The noise characteristics of symmetrical double barrier resonant tunneling structures were measured in two samples with a fixed well width of 50 Å and barrier thicknesses of LB=8 monolayer and 10 ML, respectively. The measurement was done in the frequency range of 1 Hz–100 kHz and temperature range of 77–300 K. The noise due to the excess current in the valley region, observed in both devices, was associated with defect assisted tunneling which is a two-step process: generation-recombination noise due to the trapping and detrapping mechanism, and 1/f noise due to the scattering by phonons. The current dependence of 1/f noise contribution was investigated in the resonant tunneling and valley regions. The frequency exponent of the 1/f noise component was found to vary between 0.9–1.1 for double barrier resonant tunneling diode (DBRTD) with LB=8 ML and 1.1–1.2 for DBRTD with LB=10 ML. This noise investigation implies that there is a difference in the physics governing the transport between DBRTD with LB=8 ML and DBRTD with LB=10 ML.