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

• In this paper we present recent results of experiments on atmospheric neutron radiation hardness of power MOSFETs and IGBTs.
• In order to study the effect of fast neutrons in the low energy range 1.9 MeV were chosen.
• This experiment tests the rapid aging effects of fast neutron radiation on Super Junction MOSFETs and IGBTs.
• We show that even low energy fast neutrons, can cause damage in devices biased at 650 V and above.
• The duration of the avalanche current corresponds well with the transit time of electrons through the device.

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 (1.9 MeV) experiments conducted on 650 V 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 180 MeV; 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 (100 MeV). We show that a multitude of failure modes already appear at neutron energies of 1.9 MeV 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.