Activation energy of drain-current degradation in GaN HEMTs under high-power DC stress

We have investigated the role of temperature in the degradation of GaN High-Electron-Mobility-Transistors (HEMTs) under high-power DC stress. We have identified two degradation mechanisms that take place in a sequential manner: the gate leakage current increases first, followed by a decrease in the drain current. Building on this observation, we demonstrate a new scheme to extract the activation energy (Ea) of device degradation from step-temperature measurements on a single device. The Ea's we obtain closely agree with those extracted from conventional accelerated life test experiments on a similar device technology.