Low-frequency noise in GaAs current limiters

The theory of the one-dimensional diffusion noise is modified and applied to explain the low frequency noise in GaAs current limiters. The devices show noise spectra with f ^{- {1}/{2}} and f ^{- {3}/{2}} branches. The turn-over frequency increases with the applied voltage and temperature increase. The diffusion constant depends exponentially on temperature and the activation energy varies with electric field because of Poole-Frenkel effect. The experimental data confirms the temperature and voltage dependence of noise. The calculated activation energy is very close to the value reported in connection with leakage current in GaAs MESFET. Since the diffusion constant differs by many orders of magnitude from diffusion constant of electrons or ions one-dimensional diffusion of ions along dislocation lines is proposed. However, the mechanism of diffusion is not fully understood yet.