Analysis of the Influence of Temperature on Stress Waves of Cascode GaN HEMT

The third-generation power semiconductor device gallium nitride high electron mobility transistor (GaN HEMT) is widely used in fast charging, mobile communication, and other fields due to its excellent characteristics of voltage and temperature resistance. As the core device in power electronic equipment, GaN HEMT often works under harsh conditions of high temperature and high voltage, so its status monitoring can effectively improve system reliability. Acoustic emission (AE) is a passive, fast, and real-time nondestructive state detection method. Studies have shown that GaN HEMT device will generate stress waves at the moment of switching, which can be collected by AE sensors. In this article, experiments are designed, and repeated tests are carried out under different temperatures and drain–source voltage conditions. A high-temperature-resistant AE sensor with a differential structure is used to collect stress waves of the device and found that the peak characteristic parameters and energy of the Cascode GaN HEMT will decrease when the temperature rises. In addition, the peak characteristic parameters and energy of the device have a strong positive correlation with the drain–source voltage at any temperature.