Research Progress in Breakdown Enhancement for GaN-Based High-Electron-Mobility Transistors

The breakdown characteristics are very important for GaN high-electron-mobility transistors (HEMTs), which affect the application voltage, power density, efficiency, etc. In order to further enhance the breakdown voltage of the device, it is necessary to carry out research on the breakdown mechanisms of the device. This article summarizes several breakdown mechanisms of GaN devices, including electric field concentration, buffer leakage current, gate leakage current, and vertical breakdown. In order to suppress the breakdown mechanisms, techniques such as the use of a field plate, reduced surface field (RESURF), back barrier, gate dielectric, substrate removal, and addition of AlGaN channels can be developed. With the continuous development of various technologies, the breakdown characteristics of GaN devices can be fully explored, laying the foundation for improving the performance of power electronic systems.