chapter  11
28 Pages

ELECTRICAL AND THERMAL DEGRADATION AND RELIABILITY OF GAN HEMTS

Gallium nitride high electron mobility transistors (HEMTs) find major applications in microwave and millimeter wave power devices and high-voltage power electronic devices, where they are subject constantly to strong electric fields and currents, and high junction temperature and the working conditions in high temperature applications may also affect the performance of GaN HEMTs. Therefore, the degradation mechanisms of the GaN HEMT under electrical stress and high temperature are of great significance. For GaN HEMTs, the degradation under electrical stress is of two types: the reversible and the irreversible. The reversible degradation is generally attributed to current collapse. The irreversible degradation and current collapse may occur successively or simultaneously in the same electrical and thermal stress measurements.