Gamma Ray on Superjunction MOSFET and Gate Ringing

Superjunction MOSFETs used in aircraft and spacecraft can be exposed to high-density and high-energy gamma-ray radiation environments. Commercial superjunction MOSFETs were irradiated with gamma rays in their packaged state and their static and dynamic characteristics were measured. From the double pulse test, the switching waveforms of the devices were extracted as a function of irradiation dose, and gate oscillations were observed. To provide an accurate physical analysis, a five-contact TCAD model was used and compared with the actual data. In the simulation, by dividing the gate into the gate-to-source and the gate-to-drain, and the source into the ${n}^{+}$ and the ${p}^{+}$ , we identified the parasitic capacitance characteristics of the device and analyzed the gate oscillations.