Abstract The low frequency noise spectroscopy theory for identifying traps located in the depletion region of a Field-Effect (FE) transistor is reminded. The hypothesis allowing to express the generally accepted expression of the input-referred voltage noise power spectral density related to generation-recombination (GR) phenomena is questioned. It is evidenced that the generation recombination noise formulation should be revisited in order to be physically consistent and consequently the voltage GR noise plateau should include the impact of the ratio between the dynamic channel resistance and the dynamic total resistance. It is demonstrated that in order to keep a lower shift of the quasi-Fermi level with the temperature in strong inversion operation mode it is better to maintain a constant drain current polarization over the temperature range. Considering low frequency noise measurements performed in Gate-All-Around (GAA) Nano Wire (NW) FET devices, it is also highlighted that performing only measurements over the temperature at fixed polarization is not enough in order to properly estimate the identified trap parameters. The measurements for different polarizations at fixed temperature performed for all investigated temperatures are mandatory in order to have a deep insight, in particular concerning "trapping" GR noise phenomena.
