Low-Frequency Noise Characterization in GaN HEMTs: Investigation of Deep Levels and Their Physical Properties.

In this letter, traps-related dispersion phenomenon of GaN/AlGaN/GaN high electron mobility transistor grown on the SiC substrate is investigated through low-frequency noisemeasurements. Low-frequency drain noise measurements are performed over the frequency range of 20 Hz–1MHz and for varying chuck temperatures ( T\text {chuck}) ranging between 25 °C and 125 °C. This letter demonstrates that two prominent deep levels are present in the device-under-testwith apparent activation energies ( Ea) of 0.51 and 0.57 eV, respectively. Moreover, signatures of deep level with Ea of 0.57 eV become visible only at higher operating temperatures, due to the fact that traps dispersion occurs at very low frequencies, which is confirmed through TCAD physical simulations. [ABSTRACT FROM AUTHOR]