Study On The Key Fabrication Techniques Of High-Power AlGaN/GaN HEMT

It is an important to reduce the reverse gate leakage current and heat resistanceof AlGaN/GaN HEMT when it is used as power device. In this article, the reverse characteristic of NiAu-AlGaN Schottky contact isstudied. After the surface treatment of AlGaN by O2 plasma discharge with ICP, thereverse leakage current of NiAu-AlGaN Schottky contact is reduced by two orders.It is confirmed that the oxide film of Al is important factor to reduce reverse currentby XPS. The result of research is a simple and effect method to overcome theleakage current problem during power GaN HEMT developing. The heat resistance of GaN HEMT is also studied. The simulation resultdisplays a conclusion that thinning Sapphire substrate is not effect to reduce the heatresistance. The novel flip chip bonding is developed and proved effectiveness. Thedrain saturation current is increased 10% after bonding. To disperse heat of GaNHEMT, this flip chip bonding method seems to be simple and effective.