The Investigation on Diode Surge Current Capability of Reverse Conducting IGBT and The Impact of Gate Bias

In this work, third-quadrant I-V characteristics and surge current test are carried out on two commercial RC-IGBTs (DUT A and DUT B) under different gate bias (V
GE
). The experimental results show that, compared to under -15V or OV gate bias, devices under +15V gate bias can result in 1) an increase in the on-state voltage drop under the same surge current, a decrease in 2) maximum bearable surge current and 3) maximum bearable surge energy of devices, which have an adverse effect on the surge tolerance of devices. Moreover, according to decapsulation analysis, for all devices under test, metal melting on chip surface is the main cause of surge failure. The surge current simulations show that current is more easily concentrated in monolithically integrated diodes under gate bias of +15V compared to -15V. Such a current distribution can lead to an increase in the voltage drop and more non-uniform heating of devices under +15V gate bias, resulting in a decrease of maximum bearable surge energy.