Proton induced radiation effect of SiC MOSFET under different bias

Abstract

Radiation effects of silicon carbide metal–oxide–semiconductor field-effect transistors (SiC MOSFETs) induced by 20 MeV proton under drain bias (V D = 800 V, V G = 0 V), gate bias (V D = 0 V, V G = 10 V), turn-on bias (V D = 0.5 V, V G = 4 V) and static bias (V D = 0 V, V G = 0 V) are investigated. The drain current of SiC MOSFET under turn-on bias increases linearly with the increase of proton fluence during the proton irradiation. When the cumulative proton fluence reaches 2 × 1011 p⋅cm−2, the threshold voltage of SiC MOSFETs with four bias conditions shifts to the left, and the degradation of electrical characteristics of SiC MOSFETs with gate bias is the most serious. In the deep level transient spectrum test, it is found that the defect energy level of SiC MOSFET is mainly the ON2 (E c – 1.1 eV) defect center, and the defect concentration and defect capture cross section of SiC MOSFET with proton radiation under gate bias increase most. By comparing the degradation of SiC MOSFET under proton cumulative irradiation, equivalent 1 MeV neutron irradiation and gamma irradiation, and combining with the defect change of SiC MOSFET under gamma irradiation and the non-ionizing energy loss induced by equivalent 1 MeV neutron in SiC MOSFET, the degradation of SiC MOSFET induced by proton is mainly caused by ionizing radiation damage. The results of TCAD analysis show that the ionizing radiation damage of SiC MOSFET is affected by the intensity and direction of the electric field in the oxide layer and epitaxial layer.