Cell pitch influence on the current distribution during avalanche operation of trench IGBTs: Design issues to increase UIS ruggedness

Actual design of power devices considers ruggedness in harsh operating conditions as mandatory to meet the always-increasing demand for lifetime device reliability, this being particularly true when the devices are used in safety-critical automotive applications. In this paper we show, for the first time, that a careful engineering of the standard cell geometry can shift the avalanche current from termination to active region and eventually lead to increased avalanche ruggedness without impacting the forward capability of a 1200V-rated field-stop trench IGBT designed for power traction purposes.