Reliability and robustness of SiC power devices - how to ensure the quality level established in the silicon world

Silicon carbide (SiC) based power MOSFETs deliver new horizons in power conversion efficiency, combined with an extraordinary system performance. They are key enabler to increase power density at reduced system cost in a large variety of applications. The SiC MOSFET technology acts in addition as an enabler for disruptive applications and topologies. However, as with all new technologies, it is essential that a thorough technological development and product qualification procedure is followed. Only in this way design lifetime and quality requirements for power conversion systems can be achieved. Despite the similarities to silicon, e.g. the vertical device structures, the presence of a native oxide like SiO2 or the majority of processing steps, there are still key differences related to the material properties themselves and the operating modes of the new power devices. As these differences are substantial, their impact on the final application and on the qualification processes in development and reliability must be carefully considered. This contribution describes measures to counter key failure mechanisms in order to ensure safe and reliable operation in a wide variety of applications. This approach prevents many risks that potential users would otherwise encounter, and provides a safe path to the reliable use of SiC technology.