Deep levels characterization in GaN HEMTs - Part II: Experimental and numerical evaluation of self-heating effects on the extraction of traps activation energy

In this paper, the effects of device self-heating on the extraction of traps activation energy are investigated through experimental measurements and numerical simulations. Neglecting the device temperature increase during the experimental measurements can lead to an underestimation of traps activation energies as well as nonoverlapping Arrhenius plots. It will be shown that said artifacts can be removed once device thermal resistance is known and used to correct the temperatures data points at which trap time constants are extracted. The correctness of the proposed method is also supported through numerical simulations carried out both by neglecting and considering thermal effects during the drain current transient measurements. Finally, the experimental results obtained are also suggesting a novel method for the extraction of device thermal resistance, which yielded comparable results with respect to those obtained with other experimental techniques.