IGBT with superior long-term switching behavior by asymmetric trench oxide

The continued shrinking of IGBT chips calls for new design approaches to ensure reliable and stable switching operation during the chip lifetime. We demonstrate a new asymmetric gate oxide concept with a designed variable thickness that leads to stable long-term operation in trench IGBTs and reduces the switching delay and the gate charge without sacrificing electrical performance. These claims are supported by longer-term repetitive switching experiments as well as TCAD simulations on a calibrated model.