New Technologies for Improving the High Frequency Performance of AlGaN/GaN High Electron Mobility Transistors

In this paper, we have used a combination of physical analysis, numerical simulation and experimental work to overcome some of the main challenges in AlGaN/GaN high electron mobility transistors (HEMTs) for high frequency applications. In spite of their excellent material properties, GaN-based HEMTs are still below the theoretical predictions in their high frequency performance. If the frequency performance could be improved, the superior breakdown characteristics of nitride semiconductors would make these devices the best option for power amplifiers at Ka and even W band frequencies. To achieve this goal, we have first identified some of the critical parameters that limit the high frequency performance of AlGaN/GaN HEMTs and we have demonstrated several technologies to increase the performance. Some of these technologies include deep-submicron T-gate technology, thin-body GaN HEMTs, and advanced drain delay engineering.