A concise study of neutron irradiation effects on power MOSFETs and IGBTs

Abstract

Over the past years there have been growing concerns on the adverse effects of atmospheric neutrons on power semiconductors even at sea level. In this paper we report recent results of neutron irradiation (1.9MeV) experiments conducted on 650V Super-Junction MOSFETs and Field-Stop Trench Insulated Gate Bipolar Transistors (IGBTs). The typical experiments found in literature which study the irradiation of power electronics chose a white line spectrum of neutron energies, ranging from 1 to 180MeV; however, we have deliberately chosen to study the effect of monochromatic radiation of fast neutrons, as a first in a series of experiments, to better understand the full range of interactions from fast to ultra fast neutrons (100MeV). We show that a multitude of failure modes already appear at neutron energies of 1.9MeV ranging from gate oxide degradation to single event effects (SEE). Moreover an outstanding ruggedness of devices is demonstrated, which shows no failures at 80% rated break down and below under extreme aging conditions.