High power and high efficiency GaN HEMT with WN Schottky barrier

In this paper, a high power and high efficiency L/S-band GaN HEMT with tungsten nitride (WN) Schottky barrier is presented. By employing WN Schottky barrier, the reaction between the gate electrode and AlGaN layer is minimized and the Schottky barrier reveals good thermal stability. At 2.2 GHz, the developed GaN HEMT with 1.25 mm gate periphery delivers an output power density of 3.3W/mm with 75% maximum power-added efficiency (PAE). The accelerated life test shows that the mean time to failure (MTTF) of the developed devices is 1.8×10⁷ hours at 150°C channel temperature with an activation energy of 1.5 e V. Output power more than 90 W and PAE about 70% are obtained with a 2×12 mm gate periphery packaged device between 1.14 GHz and 1.24 GHz.