Modelling the ON-state gate leakage current in p-GaN gated AlGaN/GaN HEMTs

This work investigates the ON-state gate leakage current in p-GaN gated AlGaN/GaN HEMTs, demonstrating its strong dependence on the gate geometry. By separating the contributions of the gate area and perimeter, the Schottky-related parameters were accurately extracted. In particular, a Schottky barrier height of 1.10 eV and an acceptor concentration of 2.8 × 10 18 cm −3 were determined from the area contribution using a thermionic field emission model up to 8 V forward bias, in good agreement with C V data. The perimeter current was successfully described by Poole-Frenkel emission, revealing a shallow trap state at 108 meV, likely related to plasma-induced defects at the p-GaN sidewalls. These findings provide a reliable methodology for extracting physical parameters essential for TCAD simulations and for optimizing device processing.