Generation-Recombination noise analysis in ungated HEMT structure to determinate the activation energy and capture cross-section of traps

Low frequency noise of ungated GaAs/AlGaAs two-dimensional electron gas (2 DEG) heterostructure grown by molecular beam epitaxy (MBE) was investigated over a wide range of temperatures from 4 K to 300 K. In the frequency range from 1 Hz to 100 KHz, noise power spectral densities (PSD) can be described as superposition of flicker noise, thermal noise and several generation-recombination (G-R) noise components. The temperature dependence of the (G-R) noise arising from the traps was used to deduce the thermal activation energies and cross sections. The present results are compared to those of the literature to identify the physico-chemical nature of traps responsible of the G-R noise.