MOS bipolar gate IGBT operation

Abstract

A new IGBT with a P/sup +/ diverter which is connected to the gate through a series resistance, is proposed in this paper. It was observed from simulations that providing a small current through the diverter resulted in a significant decrease in the device on-state voltage drop. Measurements on fabricated 4 kV IGBTs showed a forward voltage drop of 2.78 V (at collector current density of 100 A/cm/sup 2/) for diverter current of 10 mA (7.38 A/cm/sup 2/), as compared to 3.09 V of the conventional IGBT (without a diverter). After electron irradiation, the devices had a forward voltage drop of 5.02 V (at collector current density of 50 A/cm/sup 2/) for the same diverter current, as compared to 6.48 V for the conventional IGBTs. Furthermore, both the devices had nearly identical turn off time, and excellent latch-up current density.