Power MOSFET quality and robustness enhancement with a new QBD characterization performed at probe–die–wafer level

The quality of the gate oxide is a central parameter for power MOSFET devices dedicated to automotive applications. Reliability is systematically evaluated through electrical tests. The purpose of this study is to apply the QBD test directly at probe–die–wafer level and to correlate its results with reliability test conclusions. In other words, this new kind of QBD test is a monitor of power MOSFET robustness which helps identify extrinsic failures and the process steps responsible. In summary, it is an accurate and fast measurement method of identifying weakened parts and enhancing device quality.