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

Abstract

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 ( ${E}_{a})$ of 0.51 and 0.57 eV, respectively. Moreover, signatures of deep level with ${E}_{a}$ 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.