The impact of reactor neutron irradiation on total ionizing dose degradation in MOSFET

Three kinds of MOSFETs with thick oxide layer and long channel were designed to do experiments and analysis on the impact of reactor neutron irradiation on total ionizing dose (TID) degradation in MOSFET. The individual gamma irradiation and the sequential irradiation of reactor neutrons and gamma rays were accomplished on the transistors. The results demonstrate that reactor neutron irradiation enhanced subsequent TID degradation in MOSFET, which was further analysed by Geant4 simulation. Neutron irradiation can also induce total ionizing dose effects rather than displacement effects in MOSFETs. The mechanism of the enhanced degradation under the sequential neutron and gamma irradiation is that ionizing energy loss by incident neutrons also makes ionizing dose accumulation in MOSFET, and neutron-induced and gamma-induced TID degradation are added together, leading to more severe degradation than that under the individual gamma irradiation.