Investigation on the Activation Energy of Device Degradation and Switching Time in AlGaN/GaN HEMTs for High-Frequency Application

Abstract

In this paper, the influence of traps on the dynamic on-resistance ( $\text{R}_{\mathrm{ dson}}$ ) and switching time of AlGaN/GaN high-electron-mobility transistors is validated by means of a switching power converter with floating buck-boost topology. A new scheme based on the voltage-dependent dynamic $\text{R}_{\mathrm{ dson}}$ is proposed to extract the average activation energy of device degradation. The average activation energy obtained is 2.25 eV at 50–200 V and 2.60 eV at 200–600 V. In addition, the dynamic $\text{R}_{\mathrm{ dson}}$ is accurately extracted by a unique extraction circuit with high switching frequency up to 1 MHz and high off-state voltage up to 600 V. Meanwhile, the switching times at turn-on and turn-off transitions are captured in a floating buck-boost converter, showing that the transconductance decreases with increasing drain voltage. Furthermore, the effect of parasitic output capacitor on the dynamic $\text{R}_{\mathrm{ dson}}$ is investigated by an experimental method. Finally, a proper hard operating mode is proposed to alleviate the influence of the trapping effect on the performance of switching power converters.

Keywords

• AlGaN/GaN HEMT
• activation energy
• dynamic on-resistance
• switching time