Dynamic Behavior of Threshold Voltage and I D – V DS Kink in AlGaN/GaN HEMTs Due to Poole–Frenkel Effect

The kink effect in field-effect transistors (FETs) consists in a sudden increase in drain current, I-D, during a drain voltage sweep and leading to a higher I-D saturation value. We report new experimental data concerning the dynamic behavior of the "kink" in AlGaN/GaN HEMTs and correlate them with deep levels. The results demonstrate the role of the Poole-Frenkel effect in determining the occurrence of the kink and identify the experimental conditions that make it observable.