Degradation of AlGaN/GaN High Electron Mobility Transistors with Different AlGaN Layer Thicknesses under Strong Electric Field

The degradation of AlGaN/GaN high electron mobility transistors (HEMTs) has a close relationship with a model of traps in AlGaN barriers as a result of high electric field. We mainly discuss the impacts of strong electrical field on the AlGaN barrier thickness of AlGaN/GaN HEMTs. It is found that the device with a thin AlGaN barrier layer is more easily degraded. We study the degradation of four parameters, i.e. the gate series resistance R_Gate, channel resistance R _channel, gate current I_G,off at V_GS=-5 and V_DS=0.1 V, and drain current I_D,max at V_GS=2 and V_DS=5 V. In addition, the degradation mechanisms of the device electrical parameters are also investigated in detail.