Drain Field Plate Impact on the Hard-Switching Performance of AlGaN/GaN HEMTs

In this work, an analysis of the impact of drain field plate (FP) length on the semi-ON degradation of AlGaN/GaN high-electron-mobility transistors (HEMTs) is performed. A wafer-level characterization, by means of pulsed stress tests, reveals a faster and more severe decrease of the drain current in the linear region for the samples with longer drain FP. 2-D technology computer-aided design (TCAD) hydrodynamic simulations show that a time and field-dependent hot electrons (HEs) trapping takes place at the passivation/barrier interface. The higher drain current decrease in the longer FP samples can be ascribed to an enhanced HE trapping at the drain FP edge due to a different electric field distribution.