Heavy ion single event effect in double-trench SiC metal-oxide-semiconductor field-effect transistors

Abstract

In the paper, experiments on 208 MeV Ge ion irradiation with different source-drain bias voltages were carried out for the double-trench SiC metal–oxide–semiconductor field-effect transistors, and the physical mechanism of the single event effect was analyzed. The experimental results show that the drain leakage current of the device increases more obviously with the increase of the initial bias voltage during irradiation. When the bias voltage was 400 V during irradiation, the device has a single event burned in the fluence of 9×10<sup>4</sup> ion/cm<sup>2</sup>, and the bias voltage was 500 V, the device has a single event burned in the fluence of 3×10<sup>4</sup> ion/cm<sup>2</sup>, so when the LET value was 37.3 MeV·cm<sup>2</sup>/mg, the SEB threshold of DUTs does not exceed 400 V, which was lower than 34 % of the rated operational voltage. The post gate-characteristics test results show that the leakage current of the device with bias voltage of 100 V did not change significantly during irradiation, When the bias voltage is 200 V and 300 V, the gate leakage and the drain leakage of the device are increased, which is positively related with bias voltage. Combined with TCAD simulation further analysis device single particle effect mechanisms, the simulation results show that at low bias voltage, the heavy ion incident device generates electron-hole pairs, the electrons are quickly swept out, and the holes accumulate at the gate oxygen corner under the effect of the electric field, which combine with the source-drain bias voltage leads to the formation of leakage current channels in the gate oxygen layer. At high bias voltage, the electrons generated by the heavy ion incident move towards the junction of the N<sup>-</sup> drift layer and the N<sup>+</sup> substrate under the effect of the electric field, which further increases the electric field strength and causes significant impact ionization. The local high current density generated by the impact ionization and the load large electric field causes the lattice temperature to exceed the melting point of silicon carbide, and causes single event burnout. This work provides a reference and support for the study of radiation effect mechanism and application of silicon carbide power devices for aerospace applications.