Device reliability study of GaN HEMTs using both low frequency noise and microwave noise temperature spectroscopy

Microwave noise temperature spectroscopy is performed on gated AlGaN/GaN high electron mobility transistors as a function of gate and drain bias. The results are combined with low frequency noise (LFN) spectroscopy to understand device degradation and specific mechanisms responsible for it. It was found that channel noise temperature shows a strong dependence to channel voltage. On the other hand self-heating related power dissipation is weakly correlated to the measured noise temperature. This indicates that microwave noise temperature can act as a useful reliability characterization tool.