Terrestrial neutron induced failure rate measurement of SiC MOSFETs using China spallation neutron source

Abstract

The atmospheric neutron induced single event burnout (SEB) is observed for SiC MOSFETs by conducting irradiation at China Spallation Neutron Source (CSNS) with maximum energy close to 1.6 GeV. The failure is manifested as a sudden loss of voltage blocking ability during irradiation and a melting region is observed for the device with SEB. The SEB failure rates of SiC MOSFETs are calculated based on the experimental results. It shows that the failure rates increase exponentially with operating voltages. The measured failure rates are consistent with the results obtained at the other spallation neutron sources, which proves that the neutron beam line at CSNS is suitable for SEB testing. The information of the secondary ions produced by neutron is obtained through Monte Carlo simulations and the contributors to SEB are analyzed. A simulation method is also applied to calculate SEB failure rate by considering ionization energy deposition of secondary ions in the sensitive region of SiC devices. The simulated failure rates are also consistent with the experimental results.