Using low frequency noise method to characterize an AlGaAs/GaAs high electron mobility heterostructure

The low frequency noise (LFN) method was used to characterize a two-dimensional electron gas (2DEG) in a double AlGaAs/GaAs/AlGaAs heterojunction from room temperature to cryogenic one. Measurements on noise presented by the power spectral density (PSD) of drain voltage are analyzed as a function for different applied voltages and temperatures in the frequency range from 1 Hz to 100 kHz. PSD can be considered as a sum of different contributions (thermal noise, generation- recombination noise and 1/f noise). The experimental results of the thermal noise versus device length of the sample permitted us to estimate the contribution of the contact noise and the results showed the good quality of contacts. The generation recombination noise is studied and traps responsible for capture and emission of carriers are identified by their activation energy and capture cross-section.