A Novel IGBT With Voltage-Clamping for Turn-on Overshoot Suppression Under Hard-Switching

A 600 V-rated insulated gate bipolar transistor (IGBT) with improved turn-on transient characteristics is proposed and investigated by simulation. The proposed IGBT features a built-in voltage-clamping structure. The floating ${p}$ -body adjacent to the trench gate is clamped at an appropriately high voltage before turn-on. This slows down the hole accumulation process in the floating p -body during turn-on transient, and thus the self-charging displacement current through the gate capacitance is reduced. The increasing rate for the gate voltage ( dV GE/ dt ) is then reduced. As a result, the proposed IGBT achieves a 25% decrease in collector current ( $I_C$ ) overshoot and 34% decrease in dI C/ dt , when compared with the conventional IGBT with the same turn-on loss ( E ON), at IC = 250 A/cm2 under hard-switching. Its fabrication process is compatible with conventional trench IGBT.