Reliability studies of GaN High Electron Mobility Transistors

Most of our modern lifestyle is based on an ever expanding communication technology marked by higher frequencies and bandwidth. Nowadays used devices reach material limits and GaN possess intrinsic advantages to replace current technology. To serve as a considerable alternative, the reliability of GaN devices is a key factor. This thesis addresses the main physical degradation processes of state-of-the-art devices. The main problems of GaN are twofold: Due to the device realisation and operating conditions, large electric fields are appearing leading to a unique degradation pattern. Previous given explanation fails, and a new approach to overcome this problem could be shown in this work, alongside with solutions for field mitigation. von Cäsar, Markus