Low-frequency noise in submicron GaAs/AlxGa1−xAs Hall devices

We present systematic studies of the excess low-frequency noise in GaAs/AlxGa1−xAs heterostructure 2DES Hall devices. We studied structures of various sizes made from different wafer materials. In larger samples a significant suppression of the 1/f noise level by gating has been observed. In structures as small as (0.45×0.45) μm2 the overall noise level is significantly higher and non-Gaussian-type noise dominates at all temperatures. Random telegraph fluctuations finally limit the device miniaturization in these materials.