Punchthrough-Voltage Enhancement of AlGaN/GaN HEMTs Using AlGaN Double-Heterojunction Confinement

In this paper, we present an enhancement of punchthrough voltage in AlGaN/GaN high-electron-mobility-transistor devices by increasing the electron confinement in the transistor channel using an AlGaN buffer-layer structure. An optimized electron confinement results in a scaling of punchthrough voltage with device geometry and a significantly reduced subthreshold drain leakage current. These beneficial properties are pronounced even further if gate-recess technology is applied for device fabrication. Physical-based device simulations give insight in the respective electronic mechanisms.