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 RGate, channel resistance Rchannel, gate current IG,off at VGS = −5 and VDS = 0.1 V, and drain current ID,max at VGS = 2 and VDS = 5 V. In addition, the degradation mechanisms of the device electrical parameters are also investigated in detail. (condensed matter: electronic structure, electrical, magnetic, and optical properties)