TCAD analysis of short-circuit oscillations in IGBTs

Abstract

Insulated-Gate Bipolar Transistors (IGBTs) exhibit a gate-voltage oscillation phenomenon during short-circuit, which can result in a gate-oxide breakdown. The oscillations have been investigated through device simulations and experimental investigations of a 3.3-kV IGBT. It has been found that the oscillations are more likely to occur at low DC-link voltages, high gate voltages and low temperatures due to a charge-storage effect at the surface of the IGBT. Based on this insight, the charge-storage effect can be explained with a reduction in carrier velocity due to the electric field shape rotation during short circuit.