Reliability of GaN GIT Devices in Power Cycling Tests with RDS(on)(T) and VGS(T) for Junction Temperature Calculation

Abstract:
To investigate the reliability of GaN-based high-electron-mobility-transistors (GaN HEMTs) with p-GaN gate and ohmic contact also known as gate injection transistors (GIT) two power cycling tests have been performed. The junction temperature has been measured with two temperature sensitive electrical parameters (TSEPs) simultaneously to calculate the temperature swing during the test and the reliability of both methods has been investigated. All tested devices reached their end of life condition after exceeding the initial forward voltage drop by more than 5%. A failure analysis was performed to investigate the failure mechanisms by removal of the mold compound and cross section microscopy.