On Gate Oxide Degradation Mechanism and Chip-Related Failure Precursors of IGBT

With the wide application of insulated gate bipolar transistor (IGBT), it is becoming more and more important to understand the failure mechanisms of power electronic devices. So far, many efforts have been made to improve the IGBT reliability by condition monitoring. However, most of the existing literatures aim at the prognosis of IGBT package-related failures, such as solder fatigue and bonding wire lift-off, which rarely involves the chip-related failures. Therefore, this paper mainly focus on the failure of IGBT gate oxide degradation, which is one of the most fragile part of the semiconductor device. Firstly, the time dielectric dependent breakdown (TDDB) of IGBT is simulated by accelerated aging testing. Then, the adverse effects of gate oxide degradation on the IGBT switching characteristics are studied by double-pulse experiment. Finally, different failure precursors are comprehensively compared by sensitivity analysis to find an optimal parameter sensitive to failure but not operation conditions.