IGBT structure with electrically separated floating-p region improving turn-on dVak/dt controllability

IGBT cell structure for improving the turn-on dIc/dt controllability is presented. The difference from the conventional structure is that the floating-p region of the new structure is electrically disconnected from the trench-side-wall region. TCAD simulation suggests that the new device structure achieves better turn-on characteristics and almost the same static and turn-off characteristics compared to the conventional structure. It turned out that the high potential of the trench-side-wall region of the new structure, at the moment just before the collector current start to flow, is the cause of the improved turn-on dIc/dt controllability.