Failure Analysis and Improvement of Superjunction MOSFET under UIS Stress Condition

Reliability has increasingly become an important concern in Superjunction MOSFET (SJ-MOS) design. Failure mechanism and improvement in the process of unclamped inductive switching (UIS) are always the research focuses of SJ-MOS reliability. This paper analyzes the failed SJ-MOS devices in the UIS test, and then studies the influences of drift-region design on the avalanche durations of SJ-MOS and proposes the improvement suggestions.